主将从现.ppt

1.When he comes back,I will tell him the news.2.If he comes back,I will tell him the news.3.Toys will be dirty if you put them in the sands.4.Lily will never know this matter if you dont tell her5.They will never let you know until it happens.6.I will see your father as soon as I get there.在if,as soon as,when，once，until等引导的从句中，通常用一般现在时态，而主句用一般将来时，这就是通常所说的主将从现 If you dont catch the bus,youll go there on foot.如果你赶不上那趟车，你就要走着去那了。主将从现主将从现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。一、主句是一般将来时，那么从句常常用一般现在时如：When I grow up,Ill be a nurse and look after patients二、如果主句是祈使句，那么从句通常要用一般现在时如：Dont laugh at me when I make a mistake.三、如果主句是含有情态动词的一般现在时，根据需要从句多用一般现在时如：You should be quiet when you are in the reading room I will tell him about it when he comes.If it is fine tomorrow,we will go outside.If he has time,he will come tomorrow.If she finishes early,she can come back early.If you dont do homework,the teacher will scold you.1.If I come,I _(see)you.2.If it is fine,we_(go)for a walk.3.You will spoil it if you _(not be)careful.4.Will you help me if I _(need)you.5.They will get wet if it _(rain).6.If you eat too much,you _(get)ill.