as if 用法

as if用法

一、as if 在从句中的作用

1、在look, seem等系动词后引导表语从句

eg: She looks as if she were ten years younger.

她看起来好像年轻了十岁。

It seems as if our team is going to win.

看起来我们队要胜了。

2、引导方式状语从句

eg: She loves the boy as if she were his mother.

她爱这个男孩，就好像她是他的母亲。

The child talked to us as if he were a grow-up.

那个孩子跟我们谈起话来，像个成年人似的。

二、as if 用于省略句中

如果as if引导的从句是“主语+系动词”结构，可以省略主语和系动词，这样as if 后就只剩下名词、不定式、形容词（短语）、介词短语或分词。

eg: He acts as if (he was) a fool. 他做事像个傻子。

Tom raised his hands as if (he was going) to say something.

Tom举起手好像要说什么。

She left the room hurriedly as if (she was) angry.

她匆忙离开房间好像生气的样子。

三、as if 从句的语气及时态

1、as if 从句用于陈述句

当说话者认为句子所述的是真是的或极有可能发生或存在的事实时。

eg: It sounds as if it raining.听起来像是在下雨。

He talks as if he is drunk.从他谈话的样子来看他是醉了。

2、as if 从句用于虚拟语气

当说话人认为句子所述的不真实或极少有可能发生或存在的情况时。从句虚拟语气动词时态的形式如下：

（1）如果从句表示与现在事实相反，谓语动词用一般过去式。eg: You look as if you didn’t care.你看起来好像并不在乎。

He talks as if he knew where she was.

他说话的样子，好像他知道她在哪里似的。

（2）如果从句表示与过去事实相反，谓语动词用“had+过去分词”。eg: He talks about Rome as if he had been there before.

他说起罗马来好像他以前去过罗马似的。

The girl listened as if she had been turned to stone.

那个女孩倾听着，一动也不动，好像已经变成了石头似的。（3）如果从句表示与将来事实相反，谓语动词用“would/could might+动词原形”。

eg: He opened his mouth as if he would say something.

他张开嘴好像要说什么。

It looks as if it might snow.看起来好像要下雪了。

（4）as if 后面可以接陈述语气和虚拟语气。如果句子陈述的情况是真实的，那么只要保持时态一致即可；如果后面接的并非真实情况，则要按照虚拟语气的规则把句子形式改变（简单说就是事态倒退原则）。

eg: It seems as if it is raining outside.

外面看起来像是下雨了。（确实是下雨了）

It seems as if it was raining outside.

外面看起来像是下雨了一样。（虚拟语气。像，但没有下雨）