if主现从现的用法—if主现从现和主将从现的区别

新概念二L16语法：if 引导的条件状语从句

If引导的条件状语从句中，从句动词必须使用一般现在时来表示将来，而主句使用一般将来时。

注意：1. ‘主将从现’是历年中考的重点考点。

2.主句的一般将来时可以用can +动词原形来代替。

3. 主句的一般将来时的陈述句也可以用祈使句来代替。

4. 主句和从句都可以放在句首。

例句：

1. If you park your car in the wrong place, a traffic policeman will soon find it.

2. You will be very lucky if he lets you go without a ticket.

3. You will enjoy your stay here if you pay attention to our street signs.

4. If you receive a request like this, you cannot fail to obey it!

5. If you see him, will you tell him about it?

6. She will come to the party if she is free.

7. You will miss the train if you don't hurry.

8. Please don't disturb him if he is too busy.

用括号中所给动词的适当形式填空

1. If it ___________(rain) tomorrow, we'll put off the soccer match.

2. If the boy plays basketball well, he _________(get) into the school team.

3. You ________never_________(pass) the driving test if you don't practise hard.

4. I _______________(pick) you up at the airport if I have time then.

5. Ask me for help if you ________(have) any problem.

6. Please tell Tom to phone me if he __________(decide) to join us.

7. If they ____________(work) hard, they will surely be successful in the end.

8. If you don't slow down now, you ______________(have) a traffic accident.

9. You can have a good rest if you _________(feel) tired.

10. If you are friendly to others, they _______________(be) friends with you.