高中語法專練：iii. 條件狀語從句

iii. 條件狀語從句

1. 當主句是一般將來時時，條件狀語從句必須用一般現(xiàn)在時表將來。

We'll hold a sports meeting next Sunday if it is fine.

如果下周日是晴天我們將舉行運動會。

2. If表示正面的條件，unless表示反面的條件，unless=if ... not。

I shall go there tomorrow if it doesn't rain.

如果明天不下雨我就去那里。

I shall go there tomorrow unless it rains.

我明天要去那里除非天下雨。

3. if可以引導虛擬條件句，其他連詞不可以。

If I were you , I would not have followed his idea.

若我是你，我當初是不會聽從他的建議的。

4. if only引導的從句謂語必須用虛擬語氣。only if“只有”，從句用陳述語氣，主句語序須倒裝。

If only I were studying in a famous university now!

若我現(xiàn)在就在一所名牌大學學習該多好?。?

Only if you work hard can you pass the college entrance examination.

只有努力學習，你才能通過大學入學考試。

5. so/as long as意為“只要”。

As （So) long as you keep on trying , you will surely succeed in the end.

只要你堅持嘗試，你最終就一定能成功。

6. supposing that= suppose that表示假設。

Supposing that it rains , I won't come to school tomorrow.

假如天下雨，我明天就不上學了。

7. providing (that) = provided (that)意為“如果，只要”。

You may come providing (that) you are allowed.

許你來你就來。

I will go with you, provided (that) my expenses are paid.

只要有人給我出錢，我就同你一起去。

8. on condition that表示“以……為條件”。

You can do anything well on condition that you put your heart into it.

只要你把全部身心投入進去，就能做好任何事情。

9. in case= for fear that意為“以免，以防”。

Take an umbrella with you in case it snows .

帶上雨傘吧以免天下雪。

10. given that意為“倘若考慮到……”。

Given that he is only a child, he has done very well.

倘若考慮到他還是個孩子的話，他已經(jīng)做得很好了。

11. 可與含有if條件狀語從句的復合句進行轉(zhuǎn)換的兩個句型：

1）祈使句/名詞短語+ and/or +簡單句

Think hard and you'll have a good idea.

=If you think hard, you'll have a good idea.

仔細想一想你就會有好辦法的。

2）分詞+簡單句

Thinking hard, you'll have a good idea.

仔細想一想，你就會有好主意的。

12. 當will, shall用于條件從句中時，不表示將來時間，而表示現(xiàn)在的意愿、意圖等。

If you will listen to me , I'd like to give you a suggestion.

如果你愿意聽我說，我想給你提一條建議。

專項練習

1. I think our boat can pass the treacherous water _______ cautiously handled.

A. until

B. if

C. lest

D. with

2. I'll give you a lift _______ I get home _______ you get off.

A. before; if

B. after; as

C. if; before

D. until; before

3. You'll succeed in time _______ you study hard.

A. unless

B. as long as

C. even if

D. even though

4. The robber told him that he had better keep silent _______ he wanted to get into trouble.

A. if

B. unless

C. otherwise

D. whether

5. I have made a promise _______ anyone can tell me the secret, I'll give him a little present.

A. that if

B. that

C. when

D. so long as

6. Don't let her leave the department _______ she is not ready to.

A. if

B. though

C. unless

D. till

7. I wrote these words down _______ I should forget.

A. for

B. so

C. lest

D. since

8. We are sure to do the work well _______ we don't lose heart.

A. for

B. so long as

C. as if

D. since

9. He would be punished _______ he should make the same mistake again.

A. unless

B. if

C. provided

D. lest

10. Anyone can borrow books from this library _______ he keeps them clean and returns them in time.

A. even if

B. unless

C. so that

D. as long as

11. _______ you return those books to the library immediately, you will have to pay a fine.

A. Until

B. Unless

C. If

D. Provided

12. The parents did not allow their son to swim in the sea _______ he might have an accident some day.

A. for fear that

B. in case of

C. besides

D. and that

13. It is a gripping story and one can't put it down _______ one has finished reading it.

A. after

B. when

C. unless

D. until

14. They agreed to rent the house　 _______ the roof should be repaired.

A. on condition that

B. as soon as

C. when

D. unless

15. The more civilized man has become, _______ he is limited by the disadvantage of his environment.

A. and the more

B. the less

C. test

D. and the less

答案速查　1-5　BABBA　6—10　ACBBD　11—15　BADAB