Probing comprehension of Wh questions in an echolalic child.

Comprehension of What , Where and When Wh questions was evaluated in a four-and-one-half year old echolalic boy who displayed in therapy and at home equivocal response to various question forms. Deficits of comprehension were traced to an inadequately developed deep structure (particularly adverbials) rather than to limited knowledge of Wh transformations. Delayed development of semantic rules, as in the case of time distinctions, may block acquisition of those syntactic rules dependent upon them.