M2U1 Grammar and usagePresent perfect tense & Present perfect continuous tense一、 现在完成时1、 构成 have/has done2、用法I 表示过去发生的事对现在具有影响。1） Justin has disappeared, so Kelly is very sad.2） The boy is happy. He has caught a bird.II 表示过去开始的动作一直延续到现在或者还将持续下去。1）I have not seen Justin since Last Friday night.2) Daniel has lived in Beijing since he came to China. III 表示动作的确切时间不明确或不重要。此时下列词汇经常和现在完成时连用： already, ever, never, for, just, lately/ recently, since, yet。1） The boy has already come home.2） I haven’t heard anything from him yet.其中，for + 一段时间，since + 某个时间点。e.g. We haven’t seen him for two days. We haven’t seen him since last Monday.IV 表示到现在为止的一段时间内重复的动作。1） Some villagers say that they have seen UFOs many times.2） I have advised him to give up smoking many times, but he just won’t listen to me.V 现在完成时还可用于下列句型中：This/It is the best/ finest/ most interesting … + that- clause, This/It is the first/ second… time + that- clause, that 从句中的谓语动词一般用现在完成时。It is/ has been a period of time since + 一般过去时1） This is the best book that I have read.2） It is the first time that I have seen the film.3） It is/ has been a long time since I came to Wuxi.3、注意1）现在完成时不和明确的表示时间的词连用，如 yesterday, last week, in 1976 等。2）表示短暂意义的动词，如 begin, leave, arrive, return, stop, open, go, come, die等，不能与表示一段时间的状语连用。* Read the following sentences and say T or F .(1) He has come to Beijing since last year. F(2) He has been here for three years. T(3) He has joined the army for three years F(4) He has been a solider for 3 years. T(5) It is 3 years si...
