didn't need to do表示: 过去不必做某事, 事实上也没做。. needn't have done表示: 过去不必做某事, 但事实上做了。 John went to the station with the... [查看全文]
It is (high) time that 后面的从句谓语动词要用过去式或用should加动词原形,但should不可省略。 It is time that the children went to bed. It is high time that the children should go to bed. [查看全文]
only if表示"只有";if only则表示"如果……就好了"。If only也可用于陈述语气。 I wake up only if the alarm clock rings. 只有闹钟响了,我才会醒。 ... [查看全文]
1)用于wish后面的从句,表示与事实相反的情况,或表示将来不太可能实现的愿望。其宾语从句的动词形式为: 真实状况 wish后 ... [查看全文]
1) It is demanded / necessary / a pity + that…结构中的主语从句的谓语动词要用should 加动词原形, should 可省略。句型: (1)suggestedIt is ... [查看全文]
虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略,再把were, should或had 移到从句句首,实行倒装。 Were they here now, they could help ... [查看全文]
主句与从句的动作发生在不同的时间,这时主,从句谓语动词的虚拟语气形式因时间不同而不同,这叫做混合条件句。 If you had asked him yesterday, you would k... [查看全文]
1)时态:可以表示过去,现在和将来的情况。它的基本特点是时态退后。 a. 同现在事实相反的假设。句型 : 条件从句 主句 一般过去时 should(... [查看全文]
真实条件句用于陈述语气,假设的情况可能发生,其中 if 是如果的意思。 时态关系句型: 条件从句 主句 一般现在时 shall/will + 动词原形 ... [查看全文]