＋do，主语＋should（could…）＋ 原形 do
过去时（与现在事实条件句一样）。

If it should rain tomorrow, we would stay at home.

If I were to go to the moon one day, I could see it with my own eyes.

If you missed the film to night, you would feel sorry.

注意问题：

1、If条件句中绝对不可出现“would”。
2、根据句中的时间状语，有时可能出现“混合虚拟”的情况，即主句可能是现在的情况，条件句也许是发生在过去的情况，但都是遵守上述句型。

3、在条件句中如果出现were, had, should可省去if，将主语与这些词倒装，例如：
Had the doctor come last night, the boy would have saved.

Were I to go to the moon one day, I would see it with my own eyes.

Should it rain tomorrow, we would stay at home.

在表示命令、建议要求、惊叹时的名词性从句中需用虚拟语气，基本句型：主语＋（should）＋动词原形，如：Mother insisted that John go to bed at 9 o’clock.（宾语从句）

We suggested that the meeting should not be held.

It was required that the crops should be harvested at once.（主语从句）

The suggestion that he be invited was rejected.（同位语从句）

That is their demand that their wages be increased.（表语从句）

注意：在这种句子中绝不出现“would”“must”“could”等。

1、wish后的宾语从句：

与现在愿望不一致 主语＋过去时；I wish I were you.

与过去愿望不一致 主语＋had＋过去分词；I wish I had visited the white House when I was in the states.

与未来愿望不一致 主语＋would（could）＋原形。I wish I could meet you tomorrow at the party.

2、It’s time句型：当It’s time后用that从句时应该为：主语＋should＋原形 或 主语＋过去时，例如：

It’s time that you went to school. 或It’s time that you should go to school.

3、If only引起的感叹句相当于“How I wish＋宾语从句”
If only he could come!  他要能来就好了。

If only I had known the answer!  我要早知答案就好了。

4、would rather, as if（though）引导的句子也需使用虚拟，表示过去的情况用过去完成时，表示现在与将来的情况用过去时，如：

I’d rather you posted the letter right away.

I’d rather you had returned the book yesterday.

She loves the children as if they were hers.

Alan talked about Rome as if he had been there.

5、without, but, but for, otherwise引起的短语或句子常暗含着含蓄条件。

Without you, I would never know him.

But for your cooperation, we wouldn’t have done the work so well. = If it were not for your cooperation, we we wouldn’t have done the work so well.
注： without / but for … = If it weren’t not for…/ If it hadn’t been for …., sb …..

But that she was afraid, she would have said no.

I would be most glad to help you, but I’ am busy now.

I am busy now; otherwise I would do you the favor!

【专项训练】

1、It is important that a college student                a foreign language.

       A．will master     B．master            C．masters          D．would master

2、It is strange that she             without saying a word.

       A．should have gone out                  B．went

       C．should go out                             D．goes out

3、If my lawyer                  here last Saturday, he                      me from going.

       A．had been, would have prevented    B．had been, would prevent

       C．were, would prevent              D．were, would have prevent

4、  ――“He is a brave man.”

       ――“Yes, I wish I               his courage.”

       A．have        B．had                C．will have        D．may have

5、If it                 rain, the crops would be saved.

       A．should            B．will                 C．is going to      D．was to

6、He ordered that the medicine                    by a special plane.

       A．was sent                                     B．would be sent

       C．should send                                D．be sent

7、If you                     the medicine, you                     better now.

       A．took, would feel                          B．had taken, felt

       C．had taken, would feel                 D．took, would have felt

8、She is my sister, but she often acts as if                    my mother.

       A．is                    B．was                 C．were        D．had been

9、I went to bed early last night, but I wish I                       so.

       A．didn’t do        B．hadn’t do              C．haven’t done  D．couldn’t do

10、I’d rather he                       tomorrow afternoon.

       A．will come B．comes             C．coming           D．came

答案：

       1、B             2、A             3、A             4、B             5、A

       6、D             7、C             8、C             9、B             10、D

五、倒装句

        英语的基本句型是主语 + 谓语。如果将主语与谓语调换, 称倒装句。倒装句分全倒装句和半倒装句。

    情况:

1、当here, there, out, in, up, down等副词放在句首时, 句子需全倒装:

There goes the bell! 铃响了！          There lived an old man.        Here comes the bus.

注意:

①在这种情况下倒装仅限于不及物动词或be动词, 像go, come, mush等。

②主语如果是代词时不需倒装如Away he went. 他走远了。

2、方位状语在句首, 如:

In front of the house stopped a police car.

Nearby were two canoes in which they had come to the island.

Under the tree sat a boy.
3 、直接引语在句首, 这种情况可倒装也可不倒装

"What does it mean?" asked the boy或the boy asked.

Never shall I forget you.

At no time was the man aware of what was happening.

Little did I understand what he said to me at that time.