Introduction

Information structure is one of the theories in textual function.Halliday refers that information unit is composed by language and information unit is the basic component of information exchange （Hu Zhuanglin et al，2005）.People communicate to convey information.However，the author argues that information structure is closely associate with context.

Analysis

Halliday （1967） categorized information structure as given and new information.Givenness classifies words and information in a discourse that are already known （or given） by virtue of being common knowledge，or by having been discussed previously in the same discourse，while new information refers the information is new and cannot be determined and defined according to context.In information structure，the new information is essential，while the given information is not.For example：

A：Who broke the vase？B： Tom.

In this conversation，“Tom” is the new information and “broke the vase” is the given information.But B only gives new information，and A understands what B is talking about.This principle can be used in Chinese.

Hu Zhuanglin （2005） said given and new information form an information unit together，and givenness is supposed to be ahead of the new information.In some context，their places can be changed for special purposes.However，its not necessary to determine the positions of given and new information.Since new information is the message people want to emphasize，the positions of given and new information are flexible based on different situations.For example：

（1）A： who broke the vase？ B： Tom broke the vase.

（2）A： what did Tom do？ B： Tome broke the vase.

In dialogue （1），“Tom” is new information while “broke the vase” is given information.However，in dialogue （2），their positions switched.When there is too much special situation，the special situation becomes common.In reality，people distinguish given information from new information according to context to some extent.Nearly all conversations and texts occur in certain context.In certain context，it is much more convenient to analyze the information structure.For example，“In this job Anne were working with silver.Now silver needs to have love”，in this text，a female manager in a company which sells silver told her new employee about the essence of business.And，“needs to have love” is the new information.

Hu Zhuanglin （2005） introduces another way to determine given information and new information —— prominence.The most prominent part is information focus，the culmination of new information，symbolizing the end of the new information in an information unit.The information focus conveys the main and most important message in a context.For example，“//Now/ silver/ needs to have/ love//”，in this sentence，the tonic prominence is “love”，which means the information focus is “love”；according to the context，the new information starts on “needs”.Therefore，“needs to have love” is the new information in this sentence.In Chinese，the new information and given information are also affect by the tones.For example，the simple sentence “我喜歡你”，we can analyze it into the three different situation：

Situation 1：//我/喜欢/你//.Situation 2：//我/喜歡/你//.Situation 3：//我/喜欢/你//.

In situation 1，“我”is information focus and the new information starts from “我” and ends with “我”.In situation 2，the tonic prominence is “喜欢”，and new information is“喜欢”.Likewise，“你” is the new information in situation 3.

Conclusion

In general，the information can be identified through the tone and context of the sentence.The most prominent tone is always the information focus.Generally，we can define the positions of given information and new information based on the context.In some reading texts，context is the best way to identify information.But in spoken language，we can pay attention the the tones of the speaker and the actual situation to identify information.

Reference

[1]Halliday，M.A.K.Notes on Transitivity and Theme in English （part II）[J].Journal of Linguistics，1967（3）：199-244.

[2]胡壮麟，朱永生等.系统功能语言学概论[M].北京：北京大学出版社，2005：171-176.

作者简介

李丽梅（1993.01—），女，汉族，四川成都人，硕士研究生，研究方向：商务英语。