Abstract
AbstractThe study of “tense and aspect” includes three distinct but related concepts,tense,grammatical aspect, andlexical aspect. In nonspecialist and pedagogical literature, they are often conflated under the termtense.Tenselocates an event or situation on the time line.Grammatical aspectprovides a means of expressing one's view of a situation or event. Bothtenseandgrammatical aspectrefer to categories of verbal morphology. In contrast,lexical aspectdeals with the semantics of a predicate. For example, a predicate may express a state or an action (compareJohn seems happyandJohn swims) or an action with duration (John changed the tire) or without duration (John recognized Mary). This entry presents the general characteristics of the acquisition of second language tense–aspect systems and then considers the aspect hypothesis that links tense, grammatical aspect, and lexical aspect in three predictions concerning the emergence and spread of perfective past, imperfective past, and morphological progressive across lexical aspectual categories as well as in narrative foreground and background. The four main variables investigated with regard to the aspect hypothesis—proficiency, language transfer, input, and task effects—are also reviewed.