A car may hit you if you are not careful.
If you are not careful, a car may hit you.
No. 2 时态要素
在该句型中：①当主句是一般将来时，②当主句的谓语含有情态动词，③当主句的谓语含有want, wish, hope等动词，④当主句是祈使句时，与其连用的条件状语从句的谓语动词通常用一般现在时代替一般将来时。试体会：
If he won't come on time tomorrow, we won't know what to do.
If he doesn't come on time tomorrow, we won't know what to do.
① 借助“祈使句＋and / or＋句子（谓语通常用将来时态）”这一句型来转换。其中，and表示句意顺承；or表示转折，意为“否则”。试体会：
If you work hard, you'll pass the exam easily.
= Work hard, and you'll pass the exam easily.
= Work hard, or you won't pass the exam easily.
If there is no water, the fish may die.
= Fish may die without water.
If you help me, I'll finish my task soon.
= With your help / With the help of you, I'll finish my task soon.
It will be a pity to leave him alone at home.
= It will be a pity if we leave him alone at home.
1. Frank a film if he's free next Saturday. (2005 年北京)
A. see B. saw C. has seen D. will see
2. I am waiting for my classmate. If , I will go running by myself. (2005 年江苏盐城)
A. she doesn't come B. she won't come
C. she will come D. she is coming
3. If he harder, he will catch up with us soon. (2005年 湖南益阳)
A. study B. studies C. studying D. studied
4. — What will Bill do if he in the test?
— He will try again. (2005年 北京崇文区)
A. fail B. fails C. will fail D. is failing
5. We won't go sightseeing if tomorrow. (2005年 江苏杭州)
A. it rains B. it will rain C. it would rain D. it rained
1. Run quickly, or you will be late for school. (2004年 江苏泰州)
you , you will be late for school.
2. Take enough money with you, and you can offer to buy the dictionary. (2005年 山西太原)
You can offer to buy the dictionary .
3. It will be a pleasure for me to go there with you. (2003年 新疆课改区)
It will be a pleasure for me I with you.
4. If there is no air, none of us can live. (2004年 宁夏)
None of us can live .
5. If you run fast enough, you will catch up with them. (2003年 湖北黄冈)
, you will catch with them.