1、若与现在事实相反,条件从句的谓语用过去式(be通常用were),主句谓语用“should (would,could,might)+动词原形”:
If you took a taxi,you’d get there quicker. 如果你坐出租车去,你可以快一点到那里。(但你不坐)
2、若与过去事实相反,条件从句的谓语用过去完成时(had+过去分词),主句谓语用“should (would,could,might)+have+过去分词”:
If I’d left sooner,I’d have been on time. 要是我早点动身,我就准时到了。(但我动身太迟了)
3、若与将来事实相反,条件从句的谓语用过去式(be通常用were),主句谓语用“should (would,could,might)+动词原形”:
If he went,would you go too? 如果他去,你也去吗?(大概他不会去)
1、由that引导表示陈述意义that可省略
He says (that) he is at home. 他说他在家里。
2、由if,whether引导表示一般疑问意义(带有是否、已否、对否等)
I don’t know if /whether Wei Hua likes fish. 我不知道韦华是否喜欢鱼。
3、由 连接代词、连接副词(疑问词)引导表示特殊疑问意义
Do you know what he wants to buy? 你知道他想要买什么吗?
4、从句时态要与主句一致,当主句是一般现在时,从句根据情况使用任何时态
He says (that ) he is at home. 他说他在家里。
当主句是一般过去时,从句应使用过去某时态(一般过去时,过去进行时,过去将来时,过去完成时)
He said (that) he was at home. 他说他在家里。
1、意为“保存;保留;保持;保守”。如:
Could you keep these letters for me, please? 你能替我保存这些信吗?
2、意为“照顾;养活”等。如:
She kept her sister for a week while her sister was ill.她妹妹有病时,她照看她了一个星期。
3、意为“留下;不必还”。如:
You can keep the pen if you like it.你要是喜欢就把钢笔留下吧。
4、意为“遵守;维护”。如:
Everyone must keep the rules. 人人必须遵守规章制度。
5、意为“售;卖”。如:
The shop keeps everything you need.那家商店里出售的东西应有尽有。