英語語法知識(shí)難點(diǎn)--動(dòng)詞虛擬語氣（五）

I． 要點(diǎn)
　表示說的話不是事實(shí),，或者是不可能發(fā)生的情況，而是一種愿望,、建議或與事實(shí)相反的假設(shè)等,。一般常用于正式的書面語中。
?。?、 虛擬語氣的構(gòu)成

　注：如果條件從句謂語動(dòng)詞包含有were或had, should, could有時(shí)可將if省去, 但要倒裝,。如：
　Had you (If you had) invited us, we would have come to your party.
?。病?虛擬語氣在各種從句的應(yīng)用
?。ǎ保?在主語從句中用來表示驚奇,、惋惜,、理應(yīng)如此等,，其謂語形式是"should(可省) ＋動(dòng)詞原形"，常用于以下三種句型中,。
　句型一：It is necessary (important, natural, strange, etc) that…
　句型二：It is a pity (a shame, no wonder, etc) that…
　句型三：It is suggested (requested, proposed, desired, etc) that…
　如： It is strange that he (should) have done that.
　　　It is a pity that he (should) be so careless.
　　　It is requested that we (should) be so careless.
?。ǎ玻?在賓語從句中用于suggest, propose, move, insist, desire, demand, request, order, command等動(dòng)詞后的賓語從句中，表間接的命令和建議,。其謂語形式是"(should)+動(dòng)詞原形",。如：
I suggest that we (should) go swimming.
?。ǎ常?在表語從句中，表示間接的命令,，要求,、請(qǐng)求、建議,、決定等,，主句中的主語通常是suggestion, proposal, request, orders, idea等。從句謂語形式是"(should)＋動(dòng)詞原形",。如：
His suggestion is that we (should) leave at once.
?。ǎ矗?在同位語從句中，謂語形式是"(should)＋動(dòng)詞原形",。如：
We received order that the work be done at once.
?。ǎ担?在It is time that…句型中，其謂語動(dòng)詞形式是"動(dòng)詞的過去式"或
　"should ＋動(dòng)詞原形",should不可省,。如：
　It's time (that) we went ( should go) to school.