-译林版八年级下册英语Unit 1 Grammar重点知识及练习（含答案）

Unit 1 Past and present Grammar 语法： 一、现在完成时的构成： 1. 现在完成时的肯定句句型： 主语+have/has+过去分词... e.g. He has lived in Beijing for ten years. I have finished my homework. 2. 现在完成时的否定句句型： 主语+have/has+not+过去分词... e.g. I have not seen the movie yet. He hasn’t been to Beijing since then. 3. 现在完成时一般疑问句的构成： Have/Has+主语+过去分词...? Yes, 主语+have/has. No, 主语+haven’t/hasn’t. e.g. Have you finished your homework yet? Yes, I have. /No, I haven’t. 二、用法：以下两种情况应用现在完成时 1. 过去发生的动词或状态一直持续到现在 e.g. He has lived here since he came to Nanjing. 2. 过去完成的动作，但强调这个过去完成的动作对现在有一定的影响或产生某种结果。 e.g. I have seen that film already. (I saw it in the past and now I can still remember something about the film.) 一般过去时只用来表示过去发生了某事，并不能表明对现在产生了什么影响。 e.g. He lost his mobile phone yesterday. (We don’t know whether he has found it or not.) He has lost mobile phone already. (He can’t use it right now.) 三、判断方法： 1. 依据用法，结合句意判断。 e.g. He has taught at this school for 3 years. 2. 依据一些副词或时间状语判断。 现在完成时常和already, ever, just, never, recently, yet等副词，以及sinc