as if
as if
as if 的用法
一、as if 从句的作用
1．引导表语从句， 常与as,look, seem,feel,taste,smell,sound等系动词连用。
如：
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．
看来我们队要胜了。
It looks as if a tornado swept through your room.
好像有龙卷风席卷过你的房间。
It looks as if they''re looking for something.
他们看起来好像在找什么东西。
2. 引导方式状语从句，表示“事情是怎么做的”或“一个人或事物是什么样的”。
如：
She loves the boy as if she were his mother．
她爱这男孩，就好像她是他的妈妈一样。
The child talked to us as if he were a grown-up．
那孩子跟我们谈起话来，像个成年人似的。
She spoke to me as if she knew me.
她和我说话的神情，好像她早就认识我。
You answered the question as if you did not know this rule.
你回答的问题好像不知道这个规则似的。
二、as if 还可用于省略句中如果as if 引导的从句是“主语+系动词”结构，可省略主语和系动词，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。
如：
He acts as if （he were） a fool．
他做事像个傻子。
Tom raised his hands as if （he was going） to say something．
汤姆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 从句用陈述语气的情况。 当说话者认为句子所述的是真实的或极有可能发生或存在的事实时。
如：
It sounds as if it is 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。
The boss speaks aloud as if he is angry.
老板说话声音很高，好像他真的生气了。
He is a happy-go-luck man as if he has no worries and cares in the world.
他是一个很快乐的人，似乎无忧无虑。
2．as if 从句用虚拟语气的情况。 当说话人认为句子所述的是不真实的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时。
如：
You look as if you didn’ t care．
你看上去好像并不在乎。
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。
When a pencil is partly in a glass of water,it looks as if it were broken.
当一支铅笔部分地放在水中时，它看上去像是折断了。
（2）从句表示与过去事实相反，谓语动词用“had+过去分词”。
如：
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．
那女孩倾听着，一动也不动，像已经变成了石头似的。
Everythings in my childhood crowded in my mind as if they had just happened.
童年发生的一切都挤在我的脑海，仿佛就像刚刚发生的一样。
（3）从句表示与将来事实相反，谓语动词用“would/could/might+动词原形”。
如：
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，则要按照虚拟语气规则把句子形式改变（简单说就是时态倒退原则）。
(5) as if 在俚语中能表示反讽，功能类似"like"，举例：As if / Like you are going to do the dishes；"like"不能独立成句，但as if 能（完整句子为：as if that/it is true.），例子：甲：She said she would help me with the project. 乙：As if！
举例
it seems as if it is raining。外面看起来象是下雨了。（确实是下雨了）
it seems as if it were raining。外面看起来好像下雨一样。（虚拟语气，似乎，其实并没有下雨）