Brazilian Portuguese has been undergoing language change and exhibits variation in the morphosyntax of the spoken and written registers. Our research team (Montrul, S., Ionin, T., Grolla, E. et al.) has been examining the linguistic knowledge of adult Brazilian native speakers and the impact of schooling on their linguistic knowledge and use. I present results of a study of intra-speaker variability in language comprehension and production of morphosyntactic aspects of BP that differ in spoken and written language (inflected infinitives, clitic pronouns) and complex sentences (passive and active relative clauses). Monolingual native speakers of Brazilian Portuguese (N = 72) of different levels of education completed a battery of cognitive tests and a sentence repetition task testing morphosyntactic and complex syntax properties of Brazilian Portuguese. Both complex sentence comprehension and repetition accuracy were related to level of education. In the production task, participants with lower levels of education produced more repetition errors in morphosyntax. However, 3rd person clitics, which are undergoing diachronic extinction, were the most variable category of the morphosyntactic structures tested in all groups. Other repetition errors reflected native speaker knowledge of spoken only or spoken and written registers. Some of the patterns of language production were found to reflect the ongoing diachronic changes present in the Brazilian Portuguese language. So far, our study suggests that level of education might drive diachronic change in monolingual contexts.
