1、as if引导的从句是“主语+系动词”结构,可省略主语和系动词,只剩下名词、不定式、形容词(短语)、介词短语或分词。
例句:
She looks as if she were ten years younger. 她看起来好像年轻了十岁。
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。
3、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。
4、 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。
5、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。
(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。
(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。