八年级下册Unit10Section A-2.ppt

现在完成时 Unit 10 I’ve had this bike for three years. 现在完成时： 表示过去发生或已经完成的某一动作对现在造成的影响或结果，或从过去开始一直延续到现在的动作或保存的状态。 结构： 主语+ have / has + 动词的过去分词 一般疑问句： have / has … ? Yes, I have. No, I haven’t. Yes, she has. No, she hasn’t. 1. 现在完成时动词构成 have /has + v 过去分词 助动词 否定 haven’t hasn’t 疑问 Have you…? Has he…? 常与下列时间状语连用：just , already, yet, ever, never, before, several times 1.过去发生的动作对现在造成的影响或结果。和already，never,ever,just,before,yet等状语连用。 2.过去已经开始，持续到现在的动作或状态， 常与for或since引起的一段时间状语连用。 动词构成：have/has+v过去分词 have breakfast I have just had my breakfast. (现在我不饿) I’m not hungry now moved here in 2004 I still live here I have lived here for three years. I have lived here since 2004/three years ago. now past 2. 现在完成时动词可以表示开始于过去持续 到现在(也许还会继续进行下去)的动作或状态。 1) I have studied English since last year. 我从去年开始学习英语。 2) She has lived in Beijing for five years. 她住在北京已经五年了。 注意: come, go , leave, arrive, buy, lose, receive, join, die, bury 和marry 等动词所表示的动作是 一时的, 不能延续的, 故不能与for …, since … 等开头的表示一段时间的状语连用。不过, 这些 词用于否定句则可以与表示持续的时间状语连用， 即动作的不发生是可以持续的。 3. 现在完成时把过去的动作和现在的结果联系起来， 一般过去时只限于表示过去的动作本身, 与现在 的结果无关。现在完成时与一般过去时在意义上 的区别举例如下： I have cleaned my room. (My room is clean now.) 我已经打扫过我的房间了。 I cleaned my room last week. (I did it in the past.) 我上周打扫了我的房间。 Father has gone to Amoy. (He went to Amoy and he is not here now.) 爸爸已经去厦门了。 They have bought a dictionary. (They bought a dictionary and they have it now.) 他们买了一本字典。 注意: 现在完成时不能和明确指出时间的状语 (如: yesterday, last, year, in 1976, two days ago, just now, when she came in 等)连用， 但可以和不明确指出时间的状语(如: already, yet, ever, never, sometimes, always, often, before, once, twice, recently, lately等)连用； 也可以和表示包括现在在内的时间状语(如： today, this morning, this week, this year等)连用。 ( 1).for+表示一段时间的短语 ( 2).since+表示过去时间点的词语 ( 3).since+表示过去时间的时间状语从句 eg.I have been a teacher ______ a year. He has been at this school _______ 1992. We