Some aspects of the verb system in the language of deaf students.

Approximately 480 deaf students (age 10 to 19 years) and 60 hearing students (age eight to 10 years) were asked to judge the grammaticality of sentences containing auxiliary verbs, of sentences where the verb had been deleted, and of sentences in which the verb tense was not marked. The results indicated that deaf students have considerable difficulty with the verb system of English. This difficulty was most pronounced in the formation of tense and voice and in agreement in number and tense. A possible ordering for the acquisition of tense did emerge; from earliest to latest it is: simple past, future, present progressive, perfective, and passive. Improvement in grammaticality judgments appeared to come from an increase in recognition that incorrect sentences were ungrammatical.