Children with head injury have impairments in pragmatic language. We invest
igated speech acts, a form of pragmatic communication, after mild or severe
childhood head injury in relation to two linguistic constituents of speech
acts competence (lexical-semantic knowledge, pragmatic inference) and two
cognitive resources (world knowledge, working memory). Children with head i
njury had difficulty producing speech acts, and the magnitude of this defic
it varied with head injury severity. Within the head injury group, semantic
reference and information were unimportant for speech acts, which were, ho
wever, significantly predicted by pragmatic inference and working memory. T
he results are discussed in relation to three general issues : the effect o
f severity of childhood head injury on linguistic and cognitive morbidity;
the relation between semantic reference, pragmatic inference and more gener
al cognitive resources in the production of speech acts; and why semantic c
ompetence at a lexical level may not be sufficient for the production of pr
agmatic utterances.