語法復習五：強調句、It的用法、省略和插入語
3、省略作賓語的不定式短語，只保留to。
e.g. ---- are you going there? ---- i’d like to (go there).
he did not give me the chance, though he had promised to (give me the chance).
注意：如果該賓語是be動詞或完成時態，則須在to之后加上be或have。
e.g. ---- are you an engineer? ---- no, but i want to be.
---- he hasn’t finished the task yet. ---- well, he ought to have.
4、省略表語。
e.g. ---- are you thirsty? ---- yes, i am (thirsty).
5、同時省略幾個成分。
e.g. let’s meet at the same place as (we met) yesterday.
---- have you finished your work? ---- (i have) not (finished my work) yet.
（二）并列句中的省略
兩個并列分句中，后一個分句常省略與前一分句中相同的部分。
e.g. my father is a doctor and my mother (is) a nurse.
i study at college and my sister (studies) at high school.
（三）主從復合句中的省略
1、主句中有一些成分被省略。
e.g. (i’m) sorry to hear that you are ill.
(it is a) pity that he missed such a good chance.
2、省略了一個從句或從句的一部分，用so或not（切不可用it或that）代替。
e.g. ---- is he coming back tonight? ---- i think so.
---- is he feeling better today? ---- i’m afraid not.
這種用法常見的有：how so? why so? is that so? i hope so. he said so 及i suppose not. i believed not. i hope not等。（但i don’t think so比i think not更常用）。
（四）其它省略
1、連詞that的省略：
①、賓語從句中常省略連詞that，但也有不能省略的情況（參看“名詞性從句”等有關部分）。
②、在定語從句中，that在從句中作賓語時可省略。
③、引導主語從句、同位語從句等的連詞that一般不可省略。在表語從句中偶爾可省略。
2、不定式符號to的省略
①、并列的不定式可省去后面的to。
e.g. i told him to sit down and wait for a moment.
②、某些使役動詞（如let, make, have）及感官動詞（如see, watch, notice, hear, feel, look at和listen to等）后面作賓語補足的不定式一定要省去to，但在被動語態中須把to復原。
e.g. ---- i saw the boy fall from the tree. ---- the boy was seen to fall from the tree.
③、介詞but前若有動詞do，后面的不定式不帶to。
e.g. the boy did nothing but play.
3、在某些狀語從句中，從句的主語與主句主語一致時，可省去“主語 + be”部分。（參看“狀語從句”有關部分）
4、連詞if在部分虛擬條件句中可省略，但后面的語序有變化（參見“倒裝句”有關部分）
5、主句與從句各有一些成分省略。
e.g. the sooner (you do it), the better (it will be).