为了避免重复，句子，中某些部分常可省略。句子常可省略的有下列各部分：
1)省掉主语(多限于少数现成说法)
Thank you for your help.谢谢你的帮助。
See you tomorrow.明天见。
2)省掉谓语动词和表语等
a)省掉谓语动词
Some of us study Russian，others English.我们有的学俄语，有的学英语。(others后省掉study)
He got up earlier than I today.他今天起得比我早。(I后省掉got up)
On the right hand of Tian''anmen Square stands the Great Hall of the People，and on the left，the Museum of Chinese history ***广场的右边是人民大会堂，左边是中国历史博物馆。
(On the left后省掉stands)
b)省掉连系动词
Ma Lin is a bus-driver，his wife a conductor.马林是女共汽车司机，他的妻子是售票员。(his wife后省掉is)
His face is tanned and his hands big and strong.他的脸晒得很黑，他的双手大而有力。(hands后省掉are)
Gold is more expensive than silver.金子比银子更贵重。(silver后省掉is)
She is as tall as I.她和我一般高。(I后省掉am)
Are you ready? －Yes，I am.你准备好了吗?——是，准备好了。(am后省掉ready)
3)同时省掉句子几个部分有时好几个句子成分都被省掉，特别在表示比较的状语从句中，在对疑问句的简略回答中，以及在反意疑问句或选择疑问句中。如：
In winter it is colder in Beijing than in Guangzhou.北京的冬天比广州冷。(than后省略 it is)
She pledged herself to complete her father’s unfinished task，whatever the cost.她立誓不管付出多大代价，也要完成她父亲未完成的事业。(the cost之后省略主语和谓语动词it was)
When did you read the play?——Long age.(= I read it long ago.)你什么时候读的这个剧本?——很久以前。
Have you ever been to xinjiang? ——Never.(= I have never been there.)你到过新疆吗?——从来没有。
You are a repair worker，aren’t you?(=aren’t you a repair worker?)你是修理工，不是吗?
Has he gone or not?(= Has he gone or has he not gone?)他走了没有?
[注一]在if, when，though，as，as if(好像)等连词引导的从句中，如果从句中的主要动词是be，可以将主语和动词be省掉。如：
When you do this exercise，make changes in the sentence structure when (if) necessary.做这个练习时，必要时可以改动句子结构。(when或it之后省掉it is)
He is very good at painting，though very young.(= though he is very young)他虽然年纪很轻，但很会画画。
The boy looked as if afraid of nothing·( = as if he were afraid of nothing)那男孩看来好像什么都不怕。
上述例句中的省略从句，除if (when) necessary等成语外，其主语均须和主句的主语相同。
[注二]在下面的句子中，动词不定式符号to的后面省去了动词原形及其以后的部分。如：
You may go with them if you want to.你愿意的话，也可以和他们一起去。(to后省去go with them)
Will you be able to come? －I’d love to. But I’m busy.你来吗?——我倒很想来，可是我现在有事。(to后省去come)
