Optional Plural Agreement in Heritage Turkish Speakers' Verb Form Choices

Turkish 3rd person plural subjects are frequently used with verbs that are unmarked for number, with plural suffix omission influenced by semantic and word-order related constraints. Previous findings from judgment tasks indicate that monolingual and heritage Turkish speakers differ in the way they are affected by these constraints. This study builds and expands upon previous research by investigating the role of word order in more detail, and by examining whether the constraint weightings obtained from Uygun and Felser's (2021) acceptability judgment data are able to predict speakers' verb form choices in a timed sentence completion task. Besides confirming that word-order related constraints are information-structural in nature, our results show that heritage speakers over-produce plural-marked verbs in comparison to monolingual speakers, indicating between-group differences in constraint ranking. We interpret this as reflecting a tendency among Turkish heritage speakers to regularize the agreement system, which is not necessarily observed in metalinguistic judgment tasks.