A Corpus-based Cross-register Study On The Dynamic Relationship Between The Present Perfectand The Simple Past In Contemporary AmericanEnglish

The relationship between the diachronic change of the present perfect (PP) and the simple past tense (SP) in English has always been an important but still puzzling subject of studies on English aspect-tense system, because the two constructions are both related to past-time reference and the distinction between the two is not clear-cut in many English varieties. Even contexts labeled by temporal adverbials, like yesterday, which tends to be used with the SP, or since, which is usually combined with the PP, have become increasingly compatible with the other construction. Therefore, it is assumed that the diachronic change of the PP or the SP should not be studied individually, as was done in many previous studies, but observed from a broader perspective---the competition between the two.This study, using the largest and most balanced American English corpus, COCA (The Corpus of Contemporary American English), aims to investigate the diachronic change patterns of the PP and the SP, as well as to detect their relationship, in five different registers (Spoken, Fiction, Magazines, Newspapers and Academic). Findings show that except in the Academic register, the diachronic change of the PP or the SP is related, whether negatively (namely competitively) or positively in the other four registers and the entire corpus. To be more specific, the development of the PP and the SP are in competition only in the whole corpus data and the Spoken register, while positively related in the register of Fiction, Magazine, Newspaper, and not significantly related in Academic. Possible interpretations about the observed development trends and relationship patterns are also attempted.This research has added the dimension of register into the study of the diachronic change of the English tense-aspect system and adopted relatively more convincing statistical methods to reveal a panorama about the relationship between the development of the PP and the SP in contemporary American English, as well as analyzed comprehensively the factors contributing to its formation.