Marking in discourse: “Birds of a feather”

Subject/verb agreement and subject/predicate adjective agreement in spoken Brazilian Portuguese are subject to a parallel processing effect, such that marking leads to further marking and lack of marking leads to further lack of marking. For example, semantically plural verb tokens preceded by marked plural subjects in the same clause or other marked verb tokens with the same subject in the preceding discourse are more likely to be explicitly marked for plural than similar tokens preceded by unmarked subjects or verbs. This phenomenon is in direct contradiction to the principle of linguistic economy, since marking tends to occur precisely in those contexts in which it is most highly redundant and could therefore be discarded with no loss of information. Furthermore, the marking of successive plural tokens cannot be considered statistically independent events, since the outcome of previous marking decisions effects future marking. We propose that the parallel processing principle is a universal of language use.