Even though there are a lot of researchers, such as Tottie, 1991; Halliday, 1994; Lyons, 1997; Horn, 1978; Jespersen, 1917; Jackendoff, 1969; Kahrel and Berg, 1994, who have made great contribution to the study of negation, quite few research pay particular attention to the scope of negation, transferred negation and negative transformation.

The three patterns mentioned above increase the range of possible interpretations of natural language, and sometimes they bring confusion and understanding obstacles in the process of translating English negative structure. Therefore, this study is undertaken to systematically discuss main causes of ambiguity in English negative structure. The thesis will elaborate the three main factors which determine the interpretation of ambiguous negative sentences. Besides, the thesis will also provide some examples to illustrate these theories during the discussion of some relevant causes in addition to confirming some related theories. Actually, it will be helpful in guiding how to handle ambiguity of negation if we can realize the cause of ambiguity of negation, which is definitely not hard to understand, particularly in the practice of translation. At this point, the topic for this study has important practical value. The thesis provides not only the further proof of causes in English negative structure but also necessary material for future study as well as practical translation in this field. Among the implications, there is no doubt that proposed strategies for disambiguation are very useful in English learning and teaching; besides, recommendations for future research are also very significant for future study. According to above theoretical and practical significance, it is necessary to carry out this study.源:自'优尔.·论,文;网·www.youerw.com/

This thesis is pided into six parts, with a set of related theories and presents several examples in each part. The first part is to make a general introduction, namely, make a brief description about the study and also illustrate the important of the study. In part three, which is the main body of this thesis, the causes of ambiguity in English negative structure are presented, along with examples of different types analyzed. The following part is disambiguation which offers several ways to deal with ambiguity in English negative structure. Part Five focuses on the enlightenment this paper brings to translation. The last part of the thesis is the conclusion part which contains some findings and implications of this thesis.  

3. Causes of ambiguity 文献综述

3.1 Ambiguity by Scope of Negation

3.1.1 Definition

 As a technical and logical notion ( Ted Honderich，1995), "Scope" refers to an area where something acts, operates or has power or control. In analogy to formal logical, "scope" denotes the range governed by operators; in linguistics "scope" denotes the range of semantic reference of negation, linguistic quantifiers, as well as particles (Aoun and Li, 1993). The scope of negation is the stretch of language where negative item has a semantic effect (Quirk, 1985). In common use of English, people will have different understanding or interpretation of the language due to different identification of the scope of negation.