A discussion of grammatical disorders in aphasia considers an area of ambiguity. In the work of one researcher, impairment of logico-grammatical relations is associated with semantic aphasia, not efferent-motor aphasia. In Western studies, efferent-motor aphasia is associated with impaired comprehension and production of grammar. In order to resolve this contradiction, the study attempts to distinguish different components in grammatical processing that could account for failures on a common processing task in two aphasia types, fluent and non-fluent. The lexical functional theory of grammar is used as a basis for analysis of data from a 1981 study. It is concluded that, consistent with earlier observations, it is fluent, not non-fluent patients, who have difficulty in assessing logical relationships in sentences, and that the distinction between disorders in fluent and non-fluent aphasia is not one of simple contrast between impaired lexicon and impaired syntax. Further research is recommended. A 22-item bibliography is included. (MSE)