Abstract：Cohesion is an indispensable part in creating and analyzing discourses，however，it is greatly different from coherence. In this paper，brief introduction of cohesion and the relationship between cohesion and coherence as well as their differences are firstly discussed. Then，some specific discussions about the choice of what type of cohesion method should be employed are mentioned.

Key Words：Cohesion；Coherence；Method

1. Introduction of Cohesion

Cohesion，a semantic concept，refers to the semantic connections between linguistic components in a discourse. It exists when the interpretation of one linguistic component is dependent on another. According to Halliday and Hasan（1964），cohesion can be divided into two kinds，grammatical cohesion as well as lexical cohesion.

2. Differences and relations between cohesion and coherence

Sometimes，it is very common for people to confuse cohesion with coherence. Coherence is usually a prerequisite for the unity of discourses. Some linguists argue that cohesion is only superficial structure of discourses，which can be realized by forms of vocabulary and grammar. While coherence relates to deep meanings of those discourses，which is presented in semantic and functional relations between sentences and utterances. And Halliday and Hasan（1976）once said，discourses themselves are coherent in contexts，thus they are cohesion as well.

From my perspective，cohesion and coherence are independent，though they may influence each other to some extent，but they are not necessities for one another. And cohesion of a discourse does not always tend to be a coherent one and vice versa，as exemplified in the following case in which it is a discourse filled with cohesion but not coherent：

（1）. I bought a Ford. The car in which President Wilson rode down the Chaps Elysees was black. Black English has been widely discussed. The discussions between the presidents ended last week.

And this is an example of a discourse with coherence but not cohesion：

（2）. A：Will you go to the party the day after tomorrow？

B：My kids need to see a dentist.

From this example，the fact that words may serve no need for us to understand what others is talking about can be found. Even though there does not exist cohesion，we also know what is going on here.

3. Discussions about the Choice of Cohesion Methods

As we all know，there are several methods to choose when cohesion is needed，such as reference，ellipsis，conjunction and so on. Efforts used to deal with discourses and cognitive effects the discourses want to achieve both are factors that need to take into consideration. And the best choice of cohesion method is based on the smallest efforts and the biggest cognitive effects. As for how to choose a suitable method to deliver specific messages under varied circumstances，there are four tips Id like to talk about.

3. Pronouns

In the first place，if the discourse does not plan to achieve particular effect，the cohesion method of delivering the least message should be taken. Thus，pronouns are employed. For example：

（1）. A tutor came to my house yesterday. She teaches well.

（2）. A tutor came to my house yesterday. The beautiful woman teaches well.

In the above-mentioned examples，“she” has no extra meaning to express in the first one，it is just anaphoric；In the second discourse，“the beautiful woman” has delivered additional meaning to readers，that is，the tutor is a beautiful woman.

3. Ellipsis

Sometimes，it is more economical for the ellipsis of similar words and phrases and for the use of substitution words，and less efforts will be used in managing messages，as exemplified in the following examples：

（1）. A：Oh you didnt have to make a special trip for that，Mother.

B：I didnt（make a special trip for that）.

3. Repetition

Under another circumstance，the more dependent the back clause is on the front clause，there will be more lexical repetitions. The most suitable choice of cohesion method helps peoples understanding towards the discourse，consequently，ambiguity can be effectively avoided. Examples like：

（1）. U.S. President Donald Trump and Russian President Vladimir Putin spoke by phone Tuesday，their first such conversation since Russia condemned a U.S. military attack against Syria last month. The two leaders discussed the civil war in Syria and the escalating tensions on the Korean peninsula.

In this example，the back underlined part is based on the former underlined part to complete the referent messages.

3. Conjunction

Besides，in addition to those，there is another situation where the relation between the front and back clause is kind of abnormal and obscure. And the employment of logic conjunctions is of vital significance，with which the true meaning of the discourse can be understood by readers. For examples：

（1）. He is my boyfriend.（But）he has been dating another girl these days.

People carry their own expectations when reading discourses like that. Without but in the second clause，they may feel frustrated after getting the message of the first clause. However，if there is a but，people will have the idea of a turning point and the following facts will not shock or upset them.

4. Conclusion

In conclusion，cohesion have been commonly used in discourses. It has distinctive characteristics from coherence as well as relations with them. People need to acknowledge all kinds of cohesion methods to choose the most suitable one in order to get a better understanding of those discourses.

References

[1]Halliday，M. A. The Linguistic Study of Literary Texts[J]. Proceedings of the Ninth International Congress of Linguists. The Hague：De Gruyter. 1964

[2]Halliday，M. A. K. & Hasan，R. Cohesion in English[M]. London：Longman. 1976

[3]陳新仁. 銜接的語用認知解讀[J]. 外語學(xué)刊. 2003

[4]苗興偉. 論銜接與連貫的關(guān)系[J]. 外國語. 1998

作者簡介

楊珂（1994.05-今），女，漢族，四川成都，碩士研究生，研究方向：商務(wù)英語。

（作者單位：西南財經(jīng)大學(xué)經(jīng)貿(mào)外語學(xué)院）