if引导的条件状语从句
1. If he hard, he will get good grades.
A. study B. studies C. will study D. studied 2. I want to know if Mary to the party tomorrow. A. go B. went C. will go D. goes
3. Everyone must dress up. If you , they won’t let you in.
A. don’t B. won’t C. can’t D. mustn’t 4. Mary will go to Sanya if she a five-day trip.
A. have B. had C. will have D. has 5. If he comes late, he will miss the train.
A. and B. so C. / D. or 【归纳总结】
1. if意为“如果”，引导条件状语从句，可放在主句后，也可放在主句前，常用逗号隔开。 2. 含if引导的条件状语从句的复合句中，主句用一般将来时，从句用一般现在时 当主句为一般将来时态时。If your daughter comes, I will call you up. 当主句是祈使句时。Please stay at home if it rains tomorrow. 当主句的谓语含有can, may, must等情态动词时
If he goes on smoking, it may be very bad for his health.
主将从现 主情从现 主祈从现
【贴示】 if 还可以当“是否”讲，主要用于宾语从句，相当于whether，
从句的时态根据语境来确定。
