Time reference through verb inflection in Turkish agrammatic aphasia.

This study tested the production of tensed finite verbs and participles referring to the past and future in agrammatic speakers of Turkish. The agrammatic speakers did not make more time reference errors in tensed verbs than in participles. This is interesting because tense in general cannot therefore be the main problem, since time reference for participles lacking tense inflection is as difficult as for verbs with tense inflection. Besides that, the past tense/perfect aspect was found to be more difficult to produce for the agrammatic speakers than the future tense/imperfect aspect. None of the current theories on agrammatic deficits can explain why reference to the past/perfect aspect is more difficult than reference to future/imperfect aspect, although a similar finding was reported for Dutch by Bastiaanse [Bastiaanse, R. (2008). Production of verbs in base-position by Dutch agrammatic speakers: Inflection versus finiteness. Journal of Neurolinguistics, 21, 104-119]. We present a remoteness model of time reference to account for the data.