A Prototypical Study Of The Simple Present Tense

English tense system has always been one of the main subjects for linguists and grammarians. Tense is traditionally defined as "a grammatical category for expressing time distinctions", therefore, the present tense usually expresses present events, while past tense expresses past events. However, the simple present tense can refer to not only happening events or existing states, but also events that already happened or will happen. Since the simple present form is associated with different meanings, we may take it as a polysemic category.In the present thesis, the writer applies the prototype theory to the analysis of this phenomenon. According to the prototype theory, many categories are centered with a prototype. Whether an entity belongs to a category or not is determined by its presence or absence of the family resemblance. The writer analyzes the state use, habitual use, instantaneous use, historic use and future use of the simple present tense, and points out that all the uses of the simple present tense do share some family resemblance: the event time is connected with the present time. It is a kind of objective temporal relationship in the state use, habitual use and instantaneous use, i.e. the speech time is simultaneous with the event time. In its use referring to the past or future, this kind of relationship is psychological, i.e. in order to emphasize the vividness of the past or the certainty of the future, the speaker subjectively connects the event time to the present time.Due to this present-connectiveness, each use of the simple present tense can be regarded as a member of this category. In this category, the state use of the simple present tense is the central member (prototype), while other uses are peripheral members.