A Cognitive Study Of The Simple Past Tense

English tense system has always been one of the main subjects for linguists and grammarians. Traditional grammarians believe that the simple past tense is a grammatical category for expressing events and states that happen in the past and there is a correspondence between the simple past tense and the time it expresses. However, we find the simple past tense can also indicate events that already happened or will happen in our daily communications.In the present thesis, the writer believes the process of meaning construction is a discourse-based process. Because the subjectivity of the language users is involved in the use of language, the traditional grammar can't explain many phenomena of language about tense. The prototype theory, conceptual metaphor and grounding, although considering the subjective factors such as cognition, can't be applied to the uses of the past tense in discourse. In mental space theory, meaning is thought to be small conceptual packets built up when we think and talk. As discourse is processed, meanings are constructed by mental spaces as a result of cues, among which past tense is served as a grammatical marker. The simple past tense reflects not only local time relation between neighboring spaces, but also the shift of V-POINT and FOCUS. When mental spaces are contacted, some principles such as optimal principle and access principle play important roles in mental space construction. Therefore, mental space theory is superior in the analysis of the past tense in discourse. This thesis analyzes the uses of the past tense such as event past and state past, habitual use, uses in reported speech events, past tense in politeness, conditional and counterfactual form and past tense in discourse.Mental space theory provides a model of the connection of semantics and cognition, which combines prototype theory, conceptual metaphor and grounding. It is of great value to employ the principles such as optimal principle and access principle and the influence of tense change on the shifts of V-POINT and Focus to analyze the uses of the simple past tense, including the use in discourse.