出版社：Faculdade de Letras da Universidade Federal de Minas Gerais
摘要：Both functional and non-functional variation exist on a large scale.A typically non-functional phenomenon is subject/verb concord,where plural markers are used more often precisely in thoseenvironments in which they are unnecessary from the point ofview of communicating meaning, such as when the subject andverb are adjacent. On the other hand, the use of realized versuszero subject pronouns is fully functional: such pronouns tend tobe used more frequently in environments in which their absencewould lead to ambiguity in interpretation on the discourse level.Non-functional variation is a characteristic of phenomena that arein an advanced stage of diachronic evolution, near the end of thefunctional cycle. Functional variation can be found near thebeginning of the cycle. In this regard, variable agreement has beenoccurring for several centuries, while the marked increase infrequency of use of subject pronouns is very recent.
