ABSTRACT The purpose of this longitudinal study is to describe the acquisition of the semantics of the tense and aspect system by adult learners of English as a second language. Pilot research indicates that learners achieve native-like command of the morphosyntax of the tense and aspect system before they acquire native-like semantics. This study will document the differential development of morphosyntax and semantics by long-term observation of learners. Natural and experimental language samples will be collected from twenty learners of English over a period of one year as they move from beginning to advanced levels of proficiency. These samples will be analyzed with respect to English to determine how target-like the interlanguage system is, on the one hand, and independently, to understand the internal characteristics of the developing system, on the other. In addition, the emerging semantics will be compared across learners to ascertain the extent of target and native language influence and the universality of the developing systems. Besides describing one facet of language acquisition, the results of this study will contribute important new information about the nature of interlanguage semantics and provide evidence about the ability of the adult mind to acquire language.
