主将从现定义：主将从现是指在时间状语从句和条件状语从句中，如果主句是一般将来时，从句用一般现在时替代一般将来时。

引导条件状语从句的词if :If you ask him, he will help you.unless :I’ll go there tomorrow unless it rains.引导时间状语从句的词when , while , before , after , untill , till , since , as soon as ,1.主将从现主句是一般将来时，从句用一般现在时。

When I grow up, I’ll be a doctor.If you go to the party, you will be happy.● 2.主祈从现主句是祈使句，从句用一般现在时。

Don’t laugh at me when I make a mistake.Put it in your diary before you forget. 用记事本记下免得忘了。

● 3.主情从现主句中含有情态动词，从句用一般现在时。

You should be quiet when you are in the reading room.A baby deer can stand as soon as it’s born. 小鹿一生下来就能站着。

You can get a better job if you speak a foreign language.要是你会说一种外语，那你就会找到更好的工作。

通常出现情况1. “主将从现”见于时间状语从句As soon as I get through with my work I’ll join you. 我工作一做完就来找你们。

Before they drive any of the buses, they will have to pass a special test. 然而在驾驶公共汽车前,他们必须通过专门测验。

My mother will be very angry with me when she finds out where I’ve been. 我母亲要是知道我到过那地方一定会大怒。

We’ll pay you half up front and the other half when you’ve finished the job. 我们先付给你一半钱，剩下的一半等你干完了再付。

2. “主将从现”见于条件状语从句If (it is) necessary I will come at 6. 如有必要，我6点钟来。

If today is Wednesday, the day after tomorrow will be Friday.今天要是星期三，后天就是星期五。

If you train hard, you’ll make a good footballer.你要刻苦训练就能成为优秀的足球运动员。

If past experience is anything to go by, the plane will be late.过去的经验要是还靠得住的话，这飞机会晚点的3. “主将从现”见于让步状语从句We’ll go even if it rains. 即使下雨我们也去。

He’ll come even if he’s i11. 他即使生病也会来。

Even if he had the money, he wouldn’t buy it. 他即使有钱也不会买它。

He’ll probably say no, though it’s worth trying.他很可能不同意，但不妨去试探一下【Exercise 】1. If I come, I ________ ( see ) you.2. If it is fine, we______( go ) for a walk.3. If it rains, they _________ ( stay ) at home.4. You will spoil it if you ______ ( not be ) careful.5. We will be very much pleased if you _____( come ).6. Will you help me if I _____ ( need ) you.7. They will get wet if it ____ ( rain ).8. We will answer if we ___( can ).9. If you eat too much, you ______( get ) ill.( ) 10. ---What will Bill do if he ____in the test?---He will try again.A.failB. fails . will fail D. is failing( ) 11. Please tell her the news when she_____. OK, I will.A. comesB. will come.C. comeD. would come( ) 12. The students will plant trees if it ___ tomorrow.A. didn’t rainB. hasn’t rainedC. won’t rainD. doesn’t rain( ) 13. We__ home if there is no bus. ---Oh, what a pity!A.will walkB. have walkedC. walkedD. walk( ) 14 .If it _____ tomorrow, I’ll go by car.A. rainB. will rainC. rainsD. would rain( ) 15.If Mary____next Sunday, we will go boating together.A. will comeB. comesC. shall comeD. shouldcome( ) 16. --- Don’t forget to ask him to write to me.--- I won’t. As soon as he____, I’ll ask him to write to you.A. will comeB. cameC. comesD. is coming( )17. --- Can I go to Beijing for my holiday, Dad?--- You can when you _______ a bit older.A. will getB. getC. are gettingD. got( )18. If he _______harder, he will catch up with us soon.A. studyB. studiesC. will studyD. studied( )19. Frank ____to see his grandma if he __ free tomorrow.A. will come; will beB. comes; isC. will come; isD. comes; will be【拓展练习】（）1. If you want to learn English well, you must use it as ___ as possible.A. oftenB. longC. manyD. soon（）2. ---What will Bill do if he ____in the test? ---He will try again.A. failB. failsC. will failD. is failing( ) 3. Please tell her the news when she_____. OK, I will.A. comesB. will come.C. comeD. would come( ) 4. The students will plant trees if it ___ tomorrow.A. didn’t rainB. hasn’t rainedC. won’t rainD. doesn’t rain ( ) 5. We__ home if there is no bus.---Oh, what a pity!A. will walkB. have walkedC. walkedD. walk ( ) 6 . If it _____ t omorrow, I’ll go by car.A. rainB. will rainC. rainsD. would rain( ) 7. If Mary _______ next Sunday, we will go boating together.A. will comeB. comesC. shall comeD. should come ( )8. --- Don’t forget to ask him toto me.--- I won’t. As soon as he _______, I’ll ask him toto you.A. will comeB. cameC. comesD. is coming ( )9. --- _____ the young girl _____ the old man clean his room every day?--- Yes, she does.A. Does; helpB. Has; helpedC. Did; helpD. Do; helps ( )10. --- What does Linda often do in the evening?--- She often __ her homework, but on the evening of March 12 she ___ TV.A. does; watchesB. is doing; watchedC. does; watchedD. is doing; was watching( )11. Our geography teacher told us yesterday that the earth __ around the sun.A. was movingB. movedC. has movedD. moves ( )12. --- Do you likesilk dress? --- Yes, I do. It _______ so soft and comfortable.A. is feelingB. feelsC. has feltD. is felt ( )13. --- Can I go to Beijing for my holiday, Dad?--- You can when you _______ a bit older.A. willnbsp;B.nbsp;C. are gettingD. got ( )14. If he _______harder, he will catch up with us soon.A. studyB. studiesC. will studyD. studied ( )15. Frank _______ to see his grandma if he _______ free tomorrow.A. will come; will beB. comes; isC. will come; isD. comes; will be( ) 16. –When will you tell him the good news?--I will tell him about it as soon as he _______ back.A. comesB. cameC. will comeD. is coming( ) 17. _______ me carefully, boys and girls. Can you _______ me?A. Listen to; hearB. Hear; listen toC. Hear; hearD. Listen to; hear from( ) 18. It won’t ______ them much time to fly to Beijing from Shanghai.A. spendB. useC. takeD. pay( ) 19. –Do you like the music the Moonlight Sonata?--Yes, it ______ really beautiful.A. feelsB. soundsC. listensD. hears。