现在完成时经典讲义.doc

现 在 完 成 时一、 现在完成时基本结构肯定句 have / has + done否定句 have / has+not+done一般疑问句 Have Hasdone? Yes,have / has. No,havent / hasnt.二、用法1. 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。(汉语中常用“已经”、“过”、“了”等表达）通常与表示包括现在在内的时间副词 just，already, before, yet, never, ever 等状语连用。例如： We have just played a game. We have already sung a song. Have you enjoyed the song?注: 带already的肯定句变成否定句或疑问句时,将already要变成yet放在句末. Eg. I have already done my homework.否定句:一般疑问句:2.现在完成时表示过去已经开始，持续到现在,也许还会持续下去的动作或状态。往往和表示延续的时间状语连用。 如for、since 等引导的时间状语。（注意：句中谓语动词要用延续性动词）一段时间的表达方法有两种:for: +一段时间 for a year for two weeks for three yearsSince： 过去的某一时刻, since nine since last week 一般过去时态的时间状语从句 since you came 时间段+ ago注意:for 和since 所引导的时间状语都表示一段时间.He has been away since last week.He has been away for one week. 对划线部分提问都用How long三、注意点瞬间动词可以用于现在完成时，但不能和表示一段时间的状语连用。如可说“He has left.”但不能说“He has left for three years.” 如果要表达“他已走了三年了”可用以下几种表达法：1、用ago,使用一般过去时。 He left here three years ago.2、用“It is +一段时间since 一般过去时从句 ” It is three years since he left here. = It has been three years since he left here.3、用“ 一段时间has passed + since + 一般过去时从句”Three years has passed since he left here.4、还可用其它表示方法，把短暂性动词改为延续性动词。He has been away for three years.He has been away since he left here.四、将短暂性动词转换为延续性动词1.直接转化成延续性动词 buy catch (get) a cold borrow come/go /become 2.转换成be+名词join the army join the Party 3转换成be+形容词或副词die finish begin/start leave fall sleep close open 4.转换成 be+介词短语 go to school 五、区别 have been (to)和have gone (to)的区别： have / has been (to) 表示“曾经到过某地”，说话时此人不在那里，已经回来。侧重指经历。（常常与once/ twice/never/ever连用） have / has gone (to) 表示某人“已经去某地了”，说话时此人可能在路上或已到那里，反正不在这里。 试比较： He has been to Beijing. 他曾去过北京。 （人已回来，可能在这儿