现在完成时讲解. 定义：表示过去发生或已经完成的动作对现在造成的影响或结果，也可以表示过去 已经开始，一直延续到现在的动作或状态。二. 现在完成时的结构：I have had my lunch. （ 我已经吃过午饭了 , 也就是说我现在不饿 ）She has left. （她已经离开了,也就是说现在她人不在这里）肯定 :血* donE （过去分词订 否定.:明i 土止 1恤日覆+ 血1哼f过占汕 叩+異他 疑问.-简略答语：No,丨;i/i- + havent/hasntX否定）三. 现在完成时的标志1. 现在完成时的含义之一是过去完成的动作对现在仍有影响 , 现在完成时通常 和 ever, never, twice（once.）, so far （至U 目前为止），since, for, in the past/last few years （在过去几年）,already （肯定句）,yet （否定“还，疑问句“已经”）, just（刚刚）,before （以前）,recently （近来）等词连用。说明：already与yet都有“已经”的意思，但already常用于肯定句，并用于句中。 yet常用于否定句和疑问句，并用于句末。例如：I have already finished my homework.I havent finished my homework yet.Have you finished your homework yet?I cant find my watch now. I think I have already lost it.2. 现在完成时的含义之二是过去已经开始的动作一直延续至现在, 甚至有可能继 续延续下去,我们可以从动作“延续”的特性和“时间”点段的区分入手。 for+时段 since+过去一个时间点since+段时间+agosince+句子（一般过去时）如： She has lived here since 1999.She has live here since 10 years ago.She has lived here since she was 5 years old.四. 现在完成时的用法A.表示过去发生或已经完成的动作对现在造成的影响或结果，强调对现在 造成的影响或结果）。例如：The car has arrived .车子来了。（结果：车子已在门口）Someone has broken the window. 有人把窗户打破了。（结果：窗户仍破着） B. 表示过去已经开始，持续到现在的动作或状态，可以和表示从过去某一 时刻延续到现在（包括“现在”在内）的一段时间的状语连用，如for+时间段、since+ 过去的时间点、疑问词how long等。1）现在完成时不能单独与过去的时间状语连用，如 yesterday， last week， three years ago 等;2）不能与 when 连用 例如：My uncle has worked at this factory for five years. 我叔叔在这个工厂工作已经五年了。Mr. Black has lived in China since 2002. 自从2002年Mr. Black 一直住在中国。How long have you been here? 你来这里多久了？注意：现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如 live， teach， learn， work， study， know.延续性动词（習定句除外）例如：（1）这本书我已经买了三个月了。错误： I have bought the book for three months.正确： I have had the book for three months.（2）你哥哥参军多长时间了？错误： How long has your brother joined the army?正确： How long has your brother been in the army/been a soldier?注意：表示短暂时间动作的词，如:come, go，die, marry，buy等的完成时不能 与for，since等表示一段时间的词连用。用来持续的动作或状态或表过去重复的 动作，如live， study， be， wait等，常和since （自从）或for （经历）引导的词 语连用。如：I have lived here for more than thirty years.我已在此住了 30 多年。延续性动词与非延续性动词之间的转换leave - be away borrow - keep buy - have die - be dead begin/start - be on finish - be over fall ill -be ill get up-be upput on wear come/become/go - be here fall asleep - be asleep get to/ arrive/reach - be (in) get to know - knowjoinbe a member of / be in . (成为的一员)wake upbe awakeopen -be open用相应的延续性动词替换短暂性动词，句中谓语动词用现在完成时，时间状 语为“ for +时间段”或“since +时间点”。如：He has been in the Green China for three years.He has been a member of the Green China for three years. 他加入“绿色中国”已经三年了。The old man died 4 years ago. The old man has been dead for 4 years.He joined the Party 2 years ago. He has been in the Party for 2 years.I bought the book 5 days ago. I have had the book for 5 days.表示时间段的短语有:for+段时间（for 2 years）, since+ 从句（since he came here）, since+ 时间点名词 （ since last year, since 5 days ago）,how long; for a long time 等。五. 现在完成时态与一般过去时态的区别1、一般过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现 在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。I saw this film yesterday.（强调动作发生的时间是 yesterday。）I have seen this film.（强调对现在的影响，电影的内容已经知道了。）2、一般过去时和表示过去的具体的时间状语连用，如：.ago, last week/.In 2008, in the past, just now, the day before yesterday, yesterday . Then（那时）,that day, one day, once（从 前）现在完成时常和模糊的时间状语连用，如recently （近来），ever, never, twice, so far （到目前为止）,since， for， in the past/last few years , already （肯定句），yet （否定，疑问句）,just（刚刚）,before （以前）等。现在完成时不与表示过去的时 间状语连用。六. 比较 have/has been to、have/has gone to 和 have been inhave（has） been to.表示“曾去过某地，已经从那里回来了”，可以和 ever、 never、 twice 等连用 have（has） gone to 表示“已经去了某地，在去那里的途中或到达那里还没有回来”。have（has） been in 表示“在某地呆多长时间”，常与表示一段时间的状语连用，如： since, for, how long 等He went to Shanghai last week 上周他去了上海。He has been to Shanghai. 他（曾经）到/去过上海.（但他人现在肯定不是在上海而是回来了）He has gone to Shanghai.他已经去上海了 .（也许刚动身出发,也许已经到了 ,也许还在路上,反正他人不在这 里）Mr. Brown has been in Shanghai for three days.布朗先生来上海已经有三天了语法练习 1一、延续性动词和瞬间性动词之间的转化1. He died 10 years ago. He for 10 years / since 10 years ago.2. He borrowed the book 2 weeks ago. He the book for 2 weeks.3. He bought the motorbike a month ago.He the motorbike for a month.4. He arrived here three days ago.He here since three days ago.5. He left here 2 years ago. He from here for 2 years.6. The film began 30 minutes ago. The film for 30 minutes.7. They opened the door an hour ago. The door for an hour.8. They closed the door an hour ago. The door for an hour.9. He joined the army last year. He a member of the army for ayear.He the army for a year.It a year he joined the army.二、句型转换。1、He has never surfed, ?（改成附加疑问句）2、They have been here since 2001.（就画线部分提问） have they been here?3、The old man last year. He for a year. （die） （动词填空）4、This factory opened twenty years ago.（同义句转换）This factory for twenty years.5、Miss Green left an hour ago. （同义句转换）Miss Green an hour ago.6、Her mother has been a Party member