ABSTRACT
Cohesion is the network of lexical, grammatical and other relations that provide links between various parts of a text. This chapter draws the best known and most detailed model of cohesion available: the model outlined by Michael Halliday and Ruqaiya Hasan in Cohesion in English. Halliday and Hasan identify five main cohesive devices in English: reference, substitution, ellipsis, conjunction and lexical cohesion. The term reference is traditionally used in semantics for the relationship which holds between a word and what it points to in the real world. Halliday and Hasan divide lexical cohesion into two main categories: reiteration and collocation. Reiteration, as the name suggests, involves repetition of lexical items. The notion of lexical cohesion as being dependent on the presence of networks of lexical items rather than the presence of any specific class or type of item is important. Cohesion contributes to patterns of redundancy, and these vary both across languages and across text types.
