??为了避免重复，英语中的许多句子经常省略一个或几个成分，这种语法现象称为省略。简单句中的省略相对来说容易把握，而复合句中的省略就比较难以识别和运用。关键的是，应首先了解在何种情况下句子的某一成分才可以省略本文着重讲述复合句中的省略。一般来说，英语学习者都比较熟悉两种有关复合句的省略：（1）从属连词that在其引导的宾语从句中常省略。（2）限定性定语从句中作宾语的关系代词that，which或whom常省略。但也有一些比较复杂但又常用的省略现象并不为许，对此一定要加强认识并正确运用。

??1．以从属连词when，while，as，though，if，un-，whether．．．or等引导的状语从句中，如果谓语动词包含有动词be，且主、从句中的主语一致，或从句的主语为it，则常可省略从句的主语和谓语的一部分。
??
??If（it is）possible，I shall fly to Beijing tomorrow on business．
??Whenever（it is）necessary，he will come to help me．
??A tiger can not be tamed unless (it was）caught very young．

??2．以从属连词as，than引导的比较状语从句中，常省略一部分成分。
??He was asked to fill in the form as (it was）required．要求他按照要求填写这份表格。
??Please finish this project as soon as (it is）possible．
??He always gives more thought to others（he gives thought）to himself．他关心别人比关心自己要多。
??She gave me the impression of having more teeth than（they）were necessary for any??practicalpur她给我的印象是，她长的牙齿数目太多，超过了实际需要。

??3?不定式符号后常省略上文提及的不定式短语）。
??She asked him to pay the rent immediately,but he refused to（pay）．
??At first he didn't want to apologize，but I persuaded him to （apologize）．刚开始时他不想道歉，但我劝说他这样做了。
??I saw him kicking a football on the street, and I told him not to（kick）．

??4．并列复合句中省略主语或谓语，或同时省略主语和谓语。
??In autumn，the day is getting shorter and shorter, and the night（is getting）longer
??and longer．秋天，白昼越来越短，而夜晚越来越长。
??They tried to swim cross the channel but（they tried）in vain．
??注意：有时，so可以用来代替一个从句或从句的一部分，这一语法现象称为替代，不属于省略。这种现象常常用在有上下文联系的对话或文。
??-Will he come to attend the meeting？
??Ithink so．
??He hopes to have a scholarship，and I hope so, too．
??She became a loyal friend and remained so. 她成了一个忠诚的朋友，而且一直如此。

??5．there be结构作定语时，省略作主语的关系代词。
??They are asked to make a list of the reference books there are on the subject of? international trade.要求他们列出有关国际贸易这一题目的参考书。

??6．在the ＋比较级……，the ＋比较级的句型中，常省略动词be，有时，还可省略除the和比较级形式以外的所有其它成分。
??The older you are，the poorer your memory（will be）．年龄越大，记忆力越差。
??The more（money I can earn），the better（it will be）．多多益善。

??7．当定语从句的先行词为way，direction， distance时，常省略关系代词。
??The direction（that）you are going in is north．
??Practice is the basic way（that）we learn a foreign language well．最根本途径。

??8．虚拟语气中也有两种需要省略的情况。一种是省略连词if；一种是省略should。但是，必须注意：在虚拟语气中省略should时，句子的顺序不变，而在省略if时，句子则需要倒装。试比较下列句子：
??It was suggested that the meeting should）be postponed．有人建议将会议推迟。
Had Thomas Edison，the great inventor his money，he would have died a wealth man.如果托马斯·爱迪生这位大发明家当年把钱都存起来的话，他去世时，肯定是个大富翁。
（＝If Thomas Edison had stored his money,．．．）