Lexical knowledge, vocabulary acquisition and vocabulary learning strategies

Lexical acquisition is central to Second Language Acquisition (SLA) as vocabulary is basic to communication, and often regarded as the greatest source of problems by language learners (Segler et al., 2002). The importance of lexical knowledge is also stressed by the fact that grammatical errors still result in understandable structures, while vocabulary errors may disrupt communication (Gass, 1988).

1.1 Lexical knowledge and lexical competence

1.1.1 Breadth and depth of vocabulary knowledge

Vocabulary knowledge can be assessed from a quantitative and qualitative point of view. The former (breadth of knowledge) is related to the question, “How many words does an L2 learner need or how much vocabulary does an L2 learner know?” The size of the English lexicon has been estimated at 54,000 word families for the language as whole, and 20,000 word families for a university graduate. Studies show that an average child adds about 1,000 word families per year, and this amount is similar for a second language learner who needs to learn at least 2,000 high frequency words (West, 1953). However, recent research has shown that this amount is unsatisfactory for successful communication and reasonable text comprehension and advise to focus on the number of 3,000 high frequency words as an immediate priority (Nation and Waring, 1997).
The qualitative aspect of vocabulary knowledge (depth of knowledge) tries to answer the more complex question, “What does knowing a word mean?” Several researchers have explained when a word can be said to be acquired. The first attempt to find the explanation was made by Richards (1976), whose article is a very important contribution to learner-centred techniques concerning vocabulary acquisition (Suberviola and Méndez, 2002). According to Richard’s “Vocabulary Knowledge Framework”, knowing a word means knowing about the word’s: frequency and collocability; register; position; form; associations; meaning-concept (knowledge about the semantic value of the word); and meaning-associations (knowledge about the word’s different meanings).
Nation (1990) adds a receptive/productive feature to Richard’s list and presents questions which should be asked and answered to discover whether a person knows a word.
However, Schmitt and Meara (1997) underline the impossibility “to design a study that could capture all of the word knowledge categories” and, as a result, the important role of research in the area of connections and interrelationships between different kinds of word knowledge.

1.1.2 Factors affecting the word difficulty

Factors that increase word difficulty are usually divided into intralexical and interlexical. Intralexical factors arise from intrinsic word’s properties and they involve: pronounceability, spelling; morphological complexity; existence of similar forms; grammar; semantic factors such as specificity and register restriction; idiomaticity and multiple meaning: homonymy and polysemy (Laufer, 1997). Interlexical factors are related to the relationship between the word and familiar words in the target language and other languages, especially the mother tongue. The learner’s first language interferes with learning a second language, and this transfer may be positive or negative. Nevertheless, it is believed that lexical transfer is more beneficial than transfer at the level of phonology or syntax. As a result, it is possible to learn L2 words by associating them with L1 words (Swan, 1997; Nation, 2005). Interlexical factors of word difficulty include: language distance, cognate status and conceptual classification/semantic boundaries (Ijaz, 1986).

1.1.3 Lexical competence

Lexical competence is far more than the ability to identify a given number of words. The process by which learners acquire a great deal information about a word takes place gradually over a long period of time, and it is very elaborate (Far, 2006).
Chapelle (1994) proposes to use three components to describe vocabulary ability: the context of vocabulary use, which can influence lexical meaning; vocabulary knowledge, which include vocabulary size, knowing of word characteristics and lexicon organization, and fundamental processes; and metacognitive strategies for vocabulary use, which are also called ‘strategic competence’.
Some researchers stress the representation of lexical knowledge as a continuum, starting with either a very small familiarity with the word (Faerch et al., 1984) or a total unfamiliarity with the word (Paribakht and Wesche, 1993), and ending with the ability to use the word correctly in production.

1.1.4 Receptive versus productive aspects of vocabulary

Receptive (or passive) vocabulary consists of words which are understood by learners during reading or listening whereas productive (or active) word knowledge defines what one needs to know about a word to use it in speaking or writing. There is an agreement that receptive vocabulary precedes production and is larger than productive vocabulary; nonetheless, the size between them diminishes over learning time (Melka,1997). However, there is no clear picture regarding the point at which word knowledge is no longer receptive but productive, not to mention the process itself. Melka (1997) concludes that reception and production should be seen as degrees of knowledge – a continuum – rather than two different systems. She proposes four stages showing learner’s increasing familiarity with the word: imitation; comprehension; reproduction with assimilation; and production. Contrary to this view, Meara (1990) agrees with the notion of a continuum for production, but he sees reception as a separate and qualitatively different system.

1.1.5 The mental lexicon

The mental lexicon refers to the way words settle in the mind. Taking into account the huge number of words, an organizational structure of the mental lexicon must be extremely sophisticated. Knowing these patterns in which words are arranged can be of great help in the field of vocabulary teaching and learning (Read, 2000; Suberviola and Méndez, 2002). The main links that relate words in the mind are: co-ordination, collocation, superordination, synonymy (Aitchinson, 1996 as cited in Suberviola and Méndez, 2002).
Researchers also endeavor to present models of organization of language understanding system. These models can be classified into two types: serial (or autonomous, indirect) and parallel (or interactive, direct) models. The former supposes a flow of information through the system in one direction, with lexical access unaffected by syntactic or semantic analyses, while the latter assumes the ability of an instant access and information exchange between any two of the processing levels (Singleton, 1999).

1.1.6 Vocabulary testing

The most popular classification of vocabulary tests reflects the quantitative/qualitative division of lexical knowledge. As a result, there are tests of vocabulary breadth and vocabulary depth (Read, 2000). The former are very common and generally take the form of checklists, ranging from quite simple yes/no-type lists to computerized frequency-based lists containing pseuedowords (e.g. Meara and Buxton, 1987 as cited in Harley and Hart, 2000). According to Read (2000) tests can be divided along three dimensions, and he proposed discrete, selective and context-independent tests on the one hand, and embedded, comprehensive and context-dependent tests on the other hand; however, other combinations of the above dimensions are possible.
Vocabulary depth tests are much more problematic. One of such tests is the Vocabulary Knowledge Scale (VKS) proposed by Paribakht and Wesche (1996). They used five-point scale to assess how well each word was known:
I. I don’t remember having seen this word before
II. I have seen this word before, but I don’t know what it means.
III. I have seen this before, and I think it means _ _ _ _ _ _ . (synonym or translation)
IV. I know this word. It means _ _ _ _ _ _. (synonym or translation)
V. I can use this word in a sentence: _ _ _ _ _ _ _ _ . (Write a sentence)
(If you do this section, please also do Section IV)
Despite the fact that the VKS does not focus on multiple meanings of a word, and it is not obvious that the levels in the scale correspond to acquisition, VKS-type scales are regarded as the most reliable in tests attempting to measure depth of lexical knowledge (Segler et al., 2002; Harley and Hart, 2000).


1.2 Vocabulary acquisition

L2 vocabulary acquisition is very complex and it involves several learning processes (Ellis, 1995). The vocabulary acquisition routes are expressed by The Implicit Learning Hypothesis and Explicit Learning Hypothesis. The former came from Krashen’s views on SLA and his Input Hypothesis. Krashen identifies two kinds of linguistic knowledge: acquisition and learning. Acquisition takes place automatically in natural communication provided that the learner is focused on meaning and input is comprehensible (Ellis, 2004). The Explicit Learning Hypothesis stresses the role of learners as active processors of information, who by using vocabulary learning strategies can enhance vocabulary acquisition (Ellis, 1995).
Ellis (1995) agrees with both hypotheses, but he underlines that implicit learning occurs through “shallow processing” whereas explicit learning represents “deep processing”. He based this distinction on Craik’s (1972) Levels of Processing Model which states the quality of learning directly depends on how involved the mental manipulation of the new information is. If a learner has to analyze, synthesize, rework or associate new material with already-known information, the processing will be deeper and will give the new material a higher chance to be settled in the learner’s mind (Schmitt and Schmitt, 1993).
However, implicit and explicit attitudes have supporters on their sides. The most convincing argument in favour of implicity is the impossibility of learning so many words of both native and L2 language only through direct instruction. Therefore, extensive reading and listening is of great value in increasing a learner’s vocabulary knowledge, remembering about the fulfillment of the following factors: learners must have appropriate L2 vocabulary size and context must be rich enough with cues.
It is worth to mention that recently, a combination of both approaches, implicit and explicit, is seen to be superior to a single learning method (Zimmerman, 1994 as cited in Gu, 2003; Paribakht and Wesche, 1997). This attitude may be explained by Sharwood-Smith’s (1981) model according to which the learner can produce L2 output by: using just implicit knowledge, using just explicit knowledge and using both of them. Figure 1 (Appendix 1) represents Sharwood-Smith’s model.
2. Language Learning Strategies

2.1. Definition and classification of language learning strategies

In the last few decades there have been some major developments within the field of language education resulting in perceiving learners as active participants rather than passive recipients (Latif, 2006). As Nyikos and Oxford (1993) wrote: “learning begins with the learner”. One consequence of the above change is the greater emphasis on and use of language learning strategies (LLS).
The first research in the area of language learning strategies was carried out in the mid seventies by Rubin (1975) and Stern (1975). They identified the characteristics of successful language learners and found the use of language learning strategies to be one of the features of good language learners.
Rubin (1975) defined learning strategies as “the techniques or devices which a learner may use to acquire knowledge.” In 1981 she made a distinction between direct and indirect strategies. The former are those that contribute directly to learning and include: clarification / verification, monitoring, memorization, guessing / inductive, inferencing, deductive reasoning and practice. The indirect strategies, according to Rubin, are those that contribute to learning indirectly: creating opportunities for practice and using production tricks. Under production tricks, Rubin included communication strategies although some researchers believe that learning strategies and communication strategies are quite different presentations of language learner behaviour. As Brown (1980) suggested: “communication is the output modality and learning is the input modality.”
Rubin’s classification was entirely based on her observations of learners, particularly the good language learners. In contrast to Rubin’s typology, O’Malley and Chamot’s (1990) taxonomy was drawn from think-alouds and interviews with beginners and advanced learners. They defined language learning strategies as “the special thoughts or behaviours that individuals use to help them comprehend, learn, or retain new information.” O’Malley and Chamot proposed three primary categories of language learning strategies: metacognitive strategies (e.g. planning, monitoring, analyzing, assessing learning), cognitive strategies (e.g. elaboration, summarising, imagery, rehearsa, inferencing, organization, transfer, deducing) and social / affective strategies (e.g. questioning for clarification, cooperation, self-talk, self-encouragement). O’Malley and Chamot’s classification was based not only on their own research findings but also on Anderson’s (1983) cognitive theory. He described three stages of skill acquisition: the cognitive stage (acquisition of declarative knowledge), the associative stage (declarative knowledge is gradually taking a procedural form) and the autonomous stage (through practice performance becomes improved, refined and automatic).
The most comprehensive and detailed definition of language learning strategies is provided by Oxford (1990). According to her, language learning strategies are: “operations employed by the learner to aid the acquisition, storage, retrieval, and use of information...; specific actions taken by the learners to make learning easier, faster, more enjoyable, more self-directed, more effective, and more transferable to new situations.” Oxford lists the features of language learning strategies:
1. Contribute to the main goal, communicative competence.
2. Allow learners to become more self-directed.
3. Expand the role of teachers.
4. Are problem-oriented.
5. Are specific actions taken by the learner.
6. Involve many aspects of the learner, not just the cognitive.
7. Support learning both directly and indirectly.
8. Are not always observable.
9. Are often conscious.
10. Can be taught.
11. Are flexible.
12. Are influenced by a variety of factors. (source: Oxford, 1999, p.9)
Oxford’s definition expands the list of goals presented by O’Malley and Chamot (1990). They picture a description of what language learners do to accomplish communicative competence, consciously or unconsciously (Kudo, 1999).
What is more, Oxford’s taxonomy is one of the most accepted and comprehensive classification. Hsiao and Oxford (2002) conducted a comparative study of the three taxonomies used in the field (O’Malley and Chamot, 1990; Oxford, 1990; Rubin, 1981) and found out that the Oxford system was superior in assessing the variety of strategies reported by learners.
Oxford’s (1990;2001) model of language learning strategies consists of six categories, classified as direct: memory strategies, cognitive strategies, compensation strategies; and indirect: metacognitive strategies, affective strategies and social strategies.
Memory strategies relate to how students remember information via making connections between it. They are specific actions used by learners to create mental links that will allow new information, mostly vocabulary, to enter and remain in long-term memory. Examples are: grouping, repeating, using keywords.
Cognitive strategies relate to how students process information and structure it. Examples include: analyzing, summarizing, finding similarities between firs and foreign languages.
Compensation strategies enable students to compensate for limited knowledge. For instance, gesturing for speaking or guessing based on the context for listening or reading.
Metacognitive strategies relate to how students manage the learning process and deal with tasks. They include: planning, organizing, selecting resources, evaluating.
Affective strategies concern students’ feelings. They help learners control their emotions, motivations and attitudes about learning English. It may be, e.g. taking risks, lowering anxiety, rewarding oneself for success.
Social strategies involve learning from or/and with others and interest in culture. They include: asking for cooperation, asking questions, empathizing with others, showing interest in learning about the culture of English-speaking countries. (Oxford,1990)
In comparison to O’Malley and Chamot’s taxonomy, Oxford added compensation strategies, and separated memory strategies from cognitive strategies as the purpose of the former is not simply memorization but deeper processing and use of the language (Lan and Oxford, 2003). Moreover, Oxford broke down O’Malley and Chamot’s social/affective strategy into two categories. This emphasis on social and affective strategies may be derived from Vygotsky’s (1978) social-cognitive psychology, known also social constructivism. According to Vygotsky, a learner’s cognitive system is a result of social interaction, as a teacher or a more advanced student provides assistance thanks to which the learner progressively becomes more independent in his learning.
The six categories underlie Oxford’s Strategy Inventory for Language Learning (1990) which has been used for a great deal of research in the learning strategies field all over the world to assess learners’ strategies. It has been translated into 23 languages and used in more than 120 dissertations and theses (Lan and Oxford, 2003).
Despite the fact that Oxford’s classification is considered to be the most comprehensive, there is still some disagreement surrounding the various ways of naming, describing and classifying language learning strategies (Chamot, 2004). Although Hsiao and Oxford (2002) have found out that Oxford system is superior in assessing the variety of strategies reported by learners, in comparison to Rubin’s (1981) and Chamot and O’Malley’s (1990) taxonomies, it does not provide a fully adequate fit to the data and there is still a degree of overlap between these categories because in some cases the same strategy belonging to one category can be classified under a different one. Even Oxford cautions that “there is no complete agreement on exactly what strategies are; how many strategies exist, how they should be defined, demarcated, and categorized; and whether it is – or even will be – possible to create a real scientifically validated hierarchy of strategies” (1990, p.17).

2.2 Vocabulary Learning Strategies

Vocabulary learning strategies are a subcategory of language learning strategies. Their importance in the group of language learning strategies is shown by the fact that the majority of strategies in taxonomies presented above (e.g. Oxford’s classification, 1990) are either vocabulary learning strategies, such as all memory strategies, or can be used for vocabulary learning tasks.
The first investigation of vocabulary learning strategies as a whole was carried out by Stoffer (1995). She wrote a questionnaire which contained 53 items designed to measure vocabulary learning strategies (VOLSI – Vocabulary Learning Strategy Inventory). Stoffer discovered that the 53 VOLSI items created nine categories as follow:
1. Strategies involving authentic language use.
2. Strategies used for self-motivation.
3. Strategies used to organize words.
4. Strategies used to create mental linkages.
5. Memory strategies.
6. Strategies involving creative activities.
7. Strategies involving physical action.
8. Strategies used to overcome anxiety.
9. Auditory strategies.
Other classification was proposed by Gu and Johnson (1996). They distinguished: beliefs about vocabulary learning, metacognitive regulation, guessing strategies, dictionary strategies, note-taking strategies, memory strategies and activation strategies.
The most recent taxonomy was developed by Nation (2001) who divided vocabulary learning strategies into three groups: relating to the planning of vocabulary learning, connected with sources of vocabulary knowledge and concerning learning processes.
However, Schmitt’s (1997) classification is regarded as the most extensive (Kudo, 1999; Segler et al., 2002; Jurkovič, 2006) for several reasons: it can be standardized as a test, is based on the theory of learning strategies as well as theories of memory, is simple to use, can be administrated to learners of various educational backgrounds and target languages, and allows comparison with other research ( Catalan, 2003 as cited in Jurkovič, 2006).
Schmitt (1997) classifies vocabulary learning strategies along two dimensions. The first dimension is based on Oxford’s (1990) division of language learning strategies. He uses four of six Oxford’s categories: social, memory, cognitive and metacognitive. Schmitt introduces a fifth category – determination strategies – which are used “when faced with discovering a new word’s meaning without recourse to another person’s expertise” (p.205). To some extent, this category may be seen as an equivalent of Oxford’s compensation strategies.
The second dimension, considering different processes essential to determine the meaning of new words (discovery strategies), and remembering them for future use (consolidation strategies), was borrowed form Nation (1990).
In Schmitt’s taxonomy there are 6 main categories with 58 individual strategies in total. The number of chief categories is the result of possible combinations between the two dimensions.
It must be mentioned that vocabulary learning strategies may be classified as ranging form “shallow” to “deep”. Shallow are quicker but lead to less retention. Such strategies include, for example, guessing from context and repeating a word several times to try to fix it in the memory. Deep strategies take more time but lead to greater retention and ease of retrieval from memory. They include, for instance, making extensive use of dictionaries or building up deep knowledge through word associations and revising to ensure retention.

2.2.1 Guessing from context

Guessing from context is classified in Schmitt’s taxonomy in the discovery-determination group which underlines the fact that this strategy is more connected with a word comprehension than a word retention. To some extent, guessing form context is similar to incidental vocabulary acquisition. Kelly (1990) divides guessing from context into two types: formal guessing and contextual guessing. The former is based only on word features and poses a danger due to ‘false friends’. The latter is relied completely on context. He concludes that the best situation for guessing from context occurs when a word may be identified on the basis of form and context.
Liu and Nation (1985) claim that to guess successfully from context, learners need to know about 19 out of every 20 words (95%) of a text.
Guessing from context is often seen as a very difficult strategy to carry out successfully because of the following problems: it is imprecise; it is time consuming; it highly depends on text difficulty and learners’ level; the context must have good reading strategies; even if it leads to comprehension, it may not lead to acquisition (Huckin and Coady, 1999). The last problem is the issue of little agreement among researchers. Some investigators (Kelly, 1999) assert that guessing from context has little importance in the acquisition of a word. One of the most convincing reason of such a situation is given by Lawson and Hogben (1996) and is related to ‘deep processing’. According to them, in the case of rich context inferring word meanings is too ‘easy’ for the learner and prevents him from deeper processes.
On the other hand, Hunt and Beglar (1998) see guessing from context, especially when regularly practiced, as a powerful tool that may contribute to deeper word knowledge for advanced learners.
However, guessing from context plays an important role in vocabulary learning strategies. Schmitt (1997) found out that 74% of intermediate level learners used it; still, it cannot be the only strategy used in reading comprehension, not to mention vocabulary retention and should be used with other strategies.

2.2.2 Dictionaries

Considering three types of dictionaries: monolingual, bilingual and bilingualized, the last ones seem to be the most effective. Bilingual dictionaries may be much helpful for lower proficiency learners as they provide short, easy-to-understand definitions (Hunt and Beglar, 1998; Far, 2006) although they do have disadvantages: encourage translation, foster one-to-one precise correspondence at word level between two languages and do not describe the syntactic behaviour of words (Gu, 2003). On the other hand, monolingual dictionaries provide information about meaning, grammar and usage (Hunt and Beglar, 1998); nevertheless, they tend to be circular in their definitions and, as Thompson (1987) explains: “employ a special register which is not necessarily the most useful or rewarding for learners to be exposed to.”
Bilingualized dictionaries try to join the good features of both bilingual and monolingual dictionaries. As the former, they include L1 synonyms, and as the former they provide L2 definitions and L2 sentence examples (Hunt and Beglar, 1998).
Moreover, the above types of dictionaries are also available in various electronic forms which are more convenient to use and allow learners to search multiple sources: grammar, text usage, thesaurus, multimedia annotations such as illustrations and videos (Knight, 1994).
A lot of research has been done to assess the effectiveness of dictionaries in vocabulary learning. Bilingual dictionaries were proven to result in vocabulary learning by Luppescu and Day (1993). They found out that these dictionaries help in vocabulary learning through reading unless the unfamiliar word has numerous entries, in which case the dictionaries may confuse learners. Nonetheless, they also noticed that using dictionaries make reading longer. Knight (1994), confirming Luppescu and Day’s findings, discovered that those who used a dictionary as well as guessed from context not only learned more words immediately after reading but also remembered more after longer time. One way to explain these results is related to the DOPH: since word meaning from context is revealed too easily (shallow processing), dictionary look-up may be necessary to vocabulary retention (deep processing) (Laufer and Hill, 2000). Similar studies were carried out for electronic dictionaries; for example, Chun and Plass (1996) found that unfamiliar words were more efficiently learned when pictures and text were available. It may be explained by Poivio’s (1986, as cited in Chun and Plass, 1997) dual-coding theory according to which there are two storage systems for information: a verbal system storing symbolic representation, and a non-verbal system storing analog representation.
To conclude, dictionaries are powerful tools but very little time is provided for training in dictionary use (Summers, 1988).

2.2.3 Focusing on form: word-formation

Knowledge of lexical roots can help students predict what a word means, how a word is spelt and is useful in remembering a word (Kelly, 1991). A learner needs three skills to take advantage of affication: dividing a new word into parts; knowing the meaning of the parts; and being able to join the meaning of the parts with the meaning of the word (Nation, 1990). However, a degree to which roots and affixes indicate the meaning of whole words differs widely. Shu et al. (1995) indicates that there are two types of words: morphologically transparent words whose meaning can be easily inferenced on the basis of the word parts, even with no help from context; and morphologically opaque words whose components contribute to the meaning to a very little extent. Still, vocabulary learning strategies based on word form assisted by guess from context can help in vocabulary acquisition since most words’ meanings - although cannot be derived solely from word parts - are likely to be clear when they appear in even a little helpful context (Far, 2006).

2.2.4 Note-taking

Learners differ in what they do in note-taking: some keep vocabulary notebooks, some prepare vocabulary cards, others simply note along margins or between lines. Moreover, some students leave their notes in the order in which they were collected whereas others copy their notes after class (McCarthy, 1990). Although note-taking is one of the strategies appreciated by researchers and learners (e.g. Schmitt, 1995; Gu, 2003) little has been done so far to determine how different types of note-taking can influence vocabulary learning.

2.2.5 Word lists and repetition

Presenting words in list form can help learners memorize large number of words in a short time. However, students are likely to forget the learned words after a short time (Meara, 1995). To prevent such a problem, lists are usually used with a reading passage to give context. This way, lists not only provide a format which is easy to memorize but also ensure exposure to meaning in context. Word lists aid in organizing words, and they are helpful at the beginning level since lists become tedious as they grow in length (Critchley, 1998). One solution is suggested by Schmitt and Schmitt (1995). According to them, students should write new words on index cards: this way students are more engaged in their learning process and use the list more effectively for their own purposes.
Repetition is the easiest and the most naturally strategy people apply to memorize foreign words. Unfortunately, most studies done in this issue were carried out before the 1970s as later studies have concentrated on ‘deeper’ strategies (Gu, 2003).
There are four problems to be discussed on word lists learning: the number of repetitions needed to remember a word list, the optimum number of words to be studied at one time, the timing for repetition and repeating aloud vs. repeating silently.
More researchers agree that an astonishing amount of word pairs can be learned within a relatively short time, and not many repetitions are needed to remember L1-L2 word pairs (7 repetitions to remember all 108 English-Russian word pairs, 6 repetitions to remember 80% of 216 word pairs according to Crothers and Suppers, 1967 as cited in Gu, 2003). The list sizes depend on the difficulty level of the words on the list, e.g. if a word list does not contain a great deal of difficult words, 100 or more words can be studied at one time (Crothers and Suppers, 1967 as cited in Gu, 2003). It is also advisable for students to begin repeating newly learned words immediately after their first encounter and do it aloud as it helps better retention than silent repetition (Gu, 2003). As Kelly (1992) expressed it: “the ear does assist the eye in the long-term retention of lexis.”

2.2.6 Mnemonics

Mnemonic strategies, mnemonic devices or simply mnemonics are designed to improve one’s memory. The word mnemonic derives from the Greek godness of memory, Mnemosyne, and means: “memory enhancing” (Hrees, 1986).
Mnemonic strategies require some amount of deep processing and they work miraculously in boasting memory. Since vocabulary learning is a memory issue, they started to be used for foreign language vocabulary learning. Research in this field began with Atkinson in 1975, and since this date, mnemonic devices have been widely analyzed as a tool for acquiring and understanding of new vocabulary.
Among mnemonics there are four groups: linguistic, spatial, visual and physical mnemonic strategies.
The linguistic mnemonics are represented by the peg method and the keyword method.
The peg method is based on memorizing lists of words by linking them to familiar words or numbers by means of an image. For instance, if students try to learn words describing types of weather, they should think of the days of the week (pegs) and associate them with a certain kind of weather (e.g. Wednesday – windy), and then form a picture in their mind of the sky on such a day (Holden, 1999).
The most known and used, however, is the keyword method. There are two versions of this method: one based on the construction of visual imagery and the second based on the construction of sentences. The first step in the two versions is linking the foreign word to a keyword: a native L1 word which sounds similar to the L2 word (Atkinson, 1975). Pressley et al (1982) shows how both these versions can be used by the following illustration: “Consider, for example, the Spanish word carta meaning (postal) letter. Using the keyword cart, a learner might generate either an image of a shopping cart transporting a letter, or a sentence such as The cart carries the letter.”
The effectiveness of the keyword method in word retention has been proven by many researchers: Avila and Sadoski, 1996; Pressley et al., 1982; Nuria and Matthew, 2006).
Spatial mnemonics include the loci method (remembering words by picturing them in specific locations), spatial grouping (remembering words on a page to form different kinds of patterns), and the finger method (associating new words with fingers). Visual mnemonics consist of pictorial method (pairing pictures with words),and visual method (visualizing a word instead of using real pictures). Physical mnemonics require to enact the meaning of a word. Some teaching techniques are based on physical reenactment, among them Asher’s Total Physical Response (Holden, 1999)
Despite positive experimental results in the effectiveness of mnemonic strategies, they do have some limitations such as:
- they strongly depend on nature of words, e.g. it is very hard to use them for abstract words (Ellis, 1997),
- they help establish one of necessary meaning links; however, the applied linguist’s conception of vocabulary stresses multiple meanings and multiple dimensions of meanings (Gu, 2003),
- they are much less effective for productive purposes (Ellis, 1997),

2.2.7 Nonmnemonic elaboration techniques

One of the nonmnemonic techniques is semantic mapping which is based on a word semantic properties. In semantic mapping learners arrange words into a diagram with a key word at the centre or the top, and related words as branches linked to the main word and to each other.
Another method may be The Sentence Writing Method (or The Sentence Generate Method) in which students construct a sentence having the word to be memorized. However, learners should make a sentence from which the meaning of the word can be identified (Nielsen, 2002).

2.3 Factors affecting language learning strategies

Research has shown that strategy use and effectiveness depend on an individual’s personality, the kind of task being carried out, and the learning environment (Schmitt and Schmitt, 1993; Gu, 2003; Far, 2006). These aspects are based on Flavell’s (1979 as cited in Gu, 2003) conception of the three components of metacognitive knowledge. The person-task-context-strategy model stresses the importance of each elements and their interrelation. As a result, an analysis of learning strategies must be carried with knowing the person, task and context (Gu, 2003).
Oxford (1989; 1990) identified several personal factors which have an influence on a strategy’s usefulness:
• motivation – generally, more motivated learners use more strategies than less motivated students
• sex – females often employ greater overall strategy use than males
• age and L2 stage – students of different ages and stages of L2 learning use different strategies
• personality type – especially lack of inhibition encourage strategy use
• learning style – general attitude to language learning influence the choice of L2 learning strategies
These person-related factors are quite stable, and have a great influence on the way a learner approaches a task (Gu, 2003).
A task is an activity which is the final product in the learner’s mind. It can be seen as an individual activity which learners carry out, e.g. remembering a word, or in broader sense, it can be described as trying to master a target language. This conception of task is broader than the definition used in task-based approaches. Different types of task material and task aims given at different difficulty levels require different learning strategies. The learning environment (or the learning context) is created by social, cultural and political factors, and includes, e.g. the people in the class and the classroom atmosphere, the family relationships, and the curriculum (Gu, 2003).

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