Vocabulary is the most important single element of language learning syllabus. But, as Madrid and McLaren (1995:149) states, “vocabulary learning does not take place in a vacuum.” Vocabulary is integrated in texts; they are the bricks we insert in the structure of texts.
Halliday and Hasan (1976) establish two ways of creating cohesion in a text: grammatical cohesion and lexical cohesion. Grammatical cohesion consists of reference, ellipsis, substitution and discourse markers and conjunctions. Lexical cohesion or “the cohesive effect achieved by the selection of vocabulary” (ibid.:274) refers to reiteration and collocation.
Reiteration is a general lexical cohesive phenomenon that includes several different procedures of cohesion: the repetition of a lexical item, the use of a synonym, near-synonym or superordinate and the use of a “general noun”. Consider the following example:
I started the ascent of the peak.
It is perfectly easy.
All of them ”have in common the fact that one lexical item refers back to another, to which it is related by having a common referent.” (ibid.:278) It is interesting to note that these items of lexical cohesion are normally accompanied by a (grammatical) reference item, normally the. It should also be considered that there is a continuum from the repetition of the same lexical item to the use of pronominal reference.
However, it is also possible to have lexical cohesion without both terms having the same referent, that is, “instances of cohesion (which) are purely lexical, a function simply of the co-occurrence of lexical items, and not in any way dependent on the relation of reference.” (ibid.:283) So, there are four possibilities of lexical cohesion as far as reference is concerned: Identical, inclusive, exclusive and unrelated, as it is shown in the following example:
That boy’s going to fall if he doesn’t take care.
Those boys are always getting into trouble.
And there’s another boy standing underneath.
There’s a boy climbing that tree.
Most boys love climbing trees.
So, lexical cohesion is a textual resource which does not depend on reference; it is based solely on form. However, lexical cohesion and reference normally happen together in a given context as a way of creating texture.
General nouns are a class of nouns that is particularly important for lexical cohesion and for text creation, but which is frequently underestimated by language teachers. As we have just seen, they represent a borderline case between lexical cohesion and reference, in the same sense as they are between lexical and grammatical items (members of open and closed systems respectively).
From a lexical point, they are superordinate members of large lexical sets; they are normally accompanied by the demonstrative reference, although it can also be found with other demonstratives in tonic position (general nouns in cohesive function are never tonic).
General nouns normally convey an interpersonal attitudinal meaning of familiarity. The interpersonal meaning implies that the speaker is emotionally involved with the referent of the general noun; this attitude may be contemptuous or sympathetic.
So far we have studied cohesion created by means of pairs of words somehow associated with each other in the language. For example, a boy and a girl are cohesive items through their opposition, called complementarity. However, cohesion should even be enhanced further to include terms whose association is difficult to define in lexico-semantic terms but which occur in proximity in a given text.
Collocation is defined as the tendency of two lexical items to appear in similar contexts. This co-occurrence provokes cohesion. For instance, it would be easy to find a text on English literature where words such as poetry…literature…reader…writer…style may appear. These collocations cooperate in the creation of texture, the quality of a text being a unity.
In this unit, we have completed the scheme of textual cohesion. Grammatical and lexical cohesion are the two procedures to create texture. In a sense, the meaning of cohesion has also been enhanced to include lexical cohesion without reference, as in collocations. Halliday and Hasan (1976:285) finally states that “there is cohesion between any pair of lexical items that stand to each other in some recognizable lexicosemantic (word meaning) relation”.
Lexical cohesion is a very important topic for language teachers, related as it is to vocabulary. The use of synonyms and near-synonyms, general nouns and collocations are features of a good text but they are unfortunately frequent absent from the language learning syllabus. And it is only through the use of authentic texts that language learners may familiarise themselves with these lexical cohesion devices.