RESTRICTION OF TIME, ASPECT AND VOICE ON SENSES OF ENGLISH MODAL VERBS

Time, aspect and voice are 3 grammatical categories and they have restrictions on the senses of English modal verbs. How the senses of English modal verbs are restricted by the 3 grammatical categories has been a tough issue in both linguistic study and natural language processing. In this article, the restriction of time, aspect and voice on the senses of English modal verbs is investigated by the approach of attribute partial-ordered structure diagram. Firstly, the theoretical foundation of this study is described. Secondly, the model for word sense disambiguation (WSD) of the English modal verb "must" is built with the accuracy of 93.63%. Thirdly, the restriction of time, aspect and voice on the senses of "must" is investigated from difference angles. It is found that time, aspect and voice attributes are mainly functioning classification in the WSD of "must". Even though they do not contribute much to the accuracies of WSD of "must", they do have some restrictions to the senses of modal verbs. Past time only co-occurs with "must"(necessary) and "must"(possibility). Prograssive and perfect aspect restrict "must" to the sense of "possibility". Passive voice tends to co-occur with "must"(necessary) and "must"(permission). These findings provide significant evidence for both the semantic study and the rule extraction for WSD of the English modal verbs.