探究一：條件狀語從句結構
1._____+if+________________
e.g. You should try it by yourself if you want to know how deep the river is.
I will go to his birthday party if he invites me.
2. _______________，______
e.g. If you go into the river, you will be drowned.
If he invites me, I will go to his birthday party.
探究二：條件狀語從句時態
規則1：if引導的條件狀語從句，主語含有情態動詞can/could/must/should/may/might等時，從句用_________時態。
If it stops raining, we can go outside.
If all your answers are right, you can go to Hainan for holiday.
You may stay to dinner if you like.
規則2：if引導的條件狀語從句，表示在某種條件下某事很可能發生時，if從句用___________，主句用____________。
If it doesn’t rain tomorrow, we will have a picnic.
If he runs, he won’t be late for school.
If it rains tomorrow, we will stay at home.
規則3：if引導的條件狀語從句，主句是祈使句，從句是__________時態。
Don't wait for me，if I'm late.
Stay at home if it rains tomorrow.
Don't play basketball if you don't finish your homework
規則4：if引導的`條件狀語從句，表示在某種條件下某事一定會發生時，if從句用___________，主句也常用___________。
If you put salt into water, it disappears.
If you take a fish out of water, it dies.
If you heat (加熱)ice, it turns into water.
探究三：條件狀語從句引導詞
1. if如果
2. unless除非如果不相當於（...）
3. as long as只要...就...
You won't pass the exam unless you work hard.
As long as you get up early, you will catch the bus.
探究四：同義詞轉換
1.祈使句+and+簡單句 and表順承“那麼”
If you study hard, you will pass the exam.
＝
2.祈使句+or+簡單句 or錶轉折“否則”
If you don't hurry up, you will be late.
＝
ss與...轉換
We will go for a picnic unless it rains tomorrow.
＝
探究五：注意事項
1.主句將來時態中多用will,一般不用be going to
2.當if表示是否時,從句不是條件狀語從句，而是賓語從句,此時不遵循“主將從現”,從句該用什麼時態就用什麼時態。
e.g. I don't know if he has come here.
Tom asked if I had read the book.
3.在if引導的條件狀語從句中不能使用some，而要用any。
e.g. If you have any questions to ask, please come to my office.
學識谷
