虛擬語氣用來表達不可能或難以實現(xiàn)的愿望，與事實相反的假設，通常分為
基本的三種形式。

    1.與現(xiàn)在事實相反的虛擬：If + did / were + ……，…… would/ should/
could/ might + do （動詞原形）

    If I were you ， I would go abroad at once. （I am not you. ）

    If he knew it now ， he could help me.（He doesn't know it now. ）

    2.與過去事實相反的虛擬：If + had done + ……，…… would（might ）
have done ……

    If I had known your telephone number yesterday， I would have phoned
you.（I didn't know your telephone number.）

    If you had come here a little earlier just now， you might have met
her.（You didn't come here earlier. ）

    3.與將來事實相反的虛擬：（1 ） If + should + v. ，…… would + v.
（可能性很小）（譯作“萬一”）

    If it should rain tomorrow， you could stay at home. If I should fail，
what should Ido ？

    （2 ） If + did / were to + v ……， would + v. （完全不可能）

    If the sun were to rise in the west ， I would lend you the money.
If you finished it in 3 minutes ， I would give you my car.

    4.金牌特殊重點

    ［簡單聯(lián)想記憶］：●下列動詞后的“賓語從句”中需要用虛擬形式，即should
+ 動詞原形，shoud 在美國英語中要省略（TOEFL 語法考點）。此類常見的動詞
有：order ， ask， decide ， demand ， require， recommend， suggest
（建議）， insist （堅決要求）， advise ， etc. He suggested that we
（should） help them with English. The teacher ordered that the homework
（should） be finished within half an hour.

    ●下列名詞后的同位語從句中要用“should +動詞原形”（should可省去）
的虛擬。此類常見的名詞有：suggestion， order， request， demand ， importance，
proposal. He made a suggestion that we（should） have a fancy dress party.
I think it is a thing of importance that it （should） be done soon.

    ● It is / was important / necessary / natural / essential / advisable
/ strange / surprising， ect. + that +主語+ should + v. It is strange
that you should say such a thing. It was important that you should tell
me all the information.

    ● wish 后的賓語從句中，as if 后的狀語從句中，須用下列的虛擬形式：
主 + wish+（that） +主 + did / were （指現(xiàn)在）

    had done（指過去）

    would+ v. （指將來）

    I wish that I met my uncle now. I wish I had met my uncle yesterday.
I wish I could meet my uncle tomorrow.

    ● It is（high） time that…… + did / were ……

    It is time that you went to bed.

    ● would rather that…… + did / were ……

    I would rather that you were not here now.

    ● would sooner that…… + did / were ……

    I would sooner that you got up earlier. I would sooner that you were
not my brother.