Abstract
In the writing of English legal texts, whether the drafters or the translators of law texts can use modal verbs accurately and skillfully or not usually reflect their ability of mastering and applying legal language. In this paper, the author made a systematic exploration of the pragmatic function and translations of three modal verbs - shall, must and may, which are the most commonly used in the different types of legal texts. Of the three modal verbs, shall is the most commonly used and most powerful one. But its usage and translations are the most controversial, so it is the focus of this paper. The author quoted a large number of examples from authoritative bilingual legal texts, pointed out some cases in which the use of modal verbs belongs to the misuse or abuse, eliminated a number of errors or inaccurate translations, gave a full demonstration on the reasonable usage and translations of modal verbs, and provided some professional guidelines for the drafters and translators of English legal texts.
Keywords  legal English   modal verbs   shall   legal implicton   golden rule

在英文法律文本写作中，能否准确，娴熟地使用情态动词，通常反映文书的起草人或译者的法律语言水准。本文对各类不同法律文本中最常使用的三个情态动词——shall,must和may在文本中的语用功用和译法作了系统探索。在这三个情态动词中，shall最常使用，功能最强大，但其用法和译法也最富有争议性，因此它是本文讨论的重点。作者通过援引大量的权威双语法律文本中的例证，指出哪些情态动词在文本中属于误用或滥用，淘汰了若干错误或不确切的译法，并对其合理的用法和译法作了充分论证，为英文法律文本的作者和译者提供一些专业指引。
关键词：法律英语      情态动词      shall     法理意蕴      黄金定律

Legal English, is the language of the stylistic features of legal profession. Compared with the ordinary English, the most typical syntactic feature of legal English is the frequent use of modal verbs (Li Kexing, 2007). It is normal in legal English using modal verbs to express the meaning such as legal authorization, mandatory and prohibition. In current world’s major English-speaking countries, modal verbs can be seen everywhere in laws and regulations, contracts and legal documents. Accordingly, correct understanding and translation of modal verbs play an important role in the cross-regional promotion and implementation of different national laws.