語法系列復(fù)習(xí)專題——虛擬語氣、倒裝句型

置于句首,來表達(dá)以if引導(dǎo)的條件句的相同意思。
例如：should it rain/were it to rain tomorrow,the sports meet would be put off./had he seen you yesterday,he would have returned your book.

5)條件句或主句的省略
當(dāng)有上下文或上下句中的語言環(huán)境暗示的時(shí)候，表示虛擬語氣的從句或主句往往可以省略，以避免重復(fù)。
例如：——why didnt you attend the party yesterday?
      ——i would/should have,but i was too busy then.
i was surprised that you didnt like this job.you could have done it better.（后面省略了if you had liked it.）

6)混合時(shí)間條件句與主句
條件句與主句的動作發(fā)生的時(shí)間有先后之差，應(yīng)按各自動作時(shí)間搭配好相應(yīng)的結(jié)構(gòu)形式。
例如：if the teacher hadnt been ill yesterday,who could give us a lecture now?/if you had reviewed the lesson,you would answer the question now.

7)含蓄條件句與主句
即用without(＝but for),or(else)代替if從句。
例如：without/but for his help,we wouldnt have made such great progress.

＝if                       his help,we wouldnt have made such great progress.

2.在as if/as though引導(dǎo)的狀語從句中用法：
在as if/as though引導(dǎo)的狀語從句中，謂語動詞多用倒退一個(gè)時(shí)間段的方式來表達(dá)虛擬語氣。例如：
the man speaks as if he were a foreigner./the speaker told us a lot about that country as though he had been there many times./they talked as if they had been good friends for years.

注：as if/as though從句中不一定都要用虛擬語氣。如果情況真實(shí)性、可能性很大，就要用正常時(shí)態(tài)來描繪。例如：it looks as if it is going to rain.天看起來象要下雨。（下雨的可能性很大。）

    3.在賓語從句、表語從句、主語從句中的用法：
1） 在wish后的賓語從句中的用法：
a.與過去事實(shí)相反的愿望：賓從謂語為“had done”形式。例如：i wish i had passed yesterdays exam.要是我昨天的考試及格了該多好。
b.與現(xiàn)在事實(shí)相反的愿望：賓從謂語為“did”形式。例如：he wishes he was as clever as you./i wish i had a large room to live in.
c.表示將來愿望：賓從謂語用“would/could do”形式。例如：how i wish i would go abroad next year!

2)在suggest,propose,demand,request,require,order,insist等動詞后的賓語從句中，謂語為“(should) do”形式。例如：i suggest/propose/demand/request/require/order/
insist that he(should) be sent to the nearest hospital as soon as possible.

3)在“it is (about/high) time＋that從句”結(jié)構(gòu)中，that從句的謂語用一般過去

時(shí)或“should do”形式。例如：it is high time he                  他該開始了。