if后面接什么时态
if后面接什么时态
if有如果,倘若等意思,那么if后面接什么时态呢?下面是学习啦小编为你整理的if后面接的时态的相关资料,希望大家喜欢!
if后接的时态
一般现在时
1. 当if后面接一般现在时的动词时,表示对将来的一种推测. if sb do sth sb will/shall do sth. If you go with me, you shall be rewarded.
2. 当if后面接一般过去时的动词时,则是一种虚拟语气. if sb did sth sb...
if从句的时态
if有两个意思:“是否”和“如果”.
当做“是否”讲时一般引导宾语从句,时态依据时间状语来做决定,
如:I don't know if he will come tomorrow.
当做“如果”讲的时候,又分为两种情形:
1.真实性条件状语从句,此时遵循“主将从现”原则,即主句用将来时,而if条件状语从句用一般现在时来代替将来时.
如:If it doesn't rain tomorrow,I will go shopping with my friends.
2.虚拟性条件状语从句,初中阶段常接触对现在和对将来的虚拟,此时主句多用过去将来时(would+动词原形),而从句用一般过去时(V-ed).
如:If I knew his telephone number,I would tell you.
if从句的三种用法
1、主将从现 (主句为一般将来时,从句为一般现在时);
eg:If it rains(从句) ,I will stay at home(主句).
=I will stay at home if it rains.
2、主句含有情态动词 (must、may、can etc.)从句为一般现在时;
eg:If you drive too fast ,you may have an accident.
=You may have an accident if you drive too fast
3、主句为祈使句,从句要用一般现在时态;
eg:Don't play computer games if you don't finish your homework.
备注:
1、If 于句首时中间用逗号隔开,主句后不用逗号.
2、if 可用unless(除非...) 替换.unless= if...not...
3、注意虚拟语气 主句和从句都为一般过去式
eg:If I was a bird ,I could fly.(事实我不可能是鸟)