现在完成时 (1) 构成:现在完成时由“have/has+ 动词的过去 分词”构成。现在完成时的肯定式、否定式和疑问式及 简单回答形式（以动词study为例）：肯定式：I （You）have studied. (1) He(She, It) has studied. (2) We(You,They) have studied. (3) 否定式I(You) have not/havent studied. (4) He(She,It)has not/hasnt studied. We(You,They) have not/ havent studied. 疑问式：Have I( you ) studied? Yes, you (I) have./No,you (I) havent. Has he (she,it) studied? Yes,he(she,it) has.No,he(she,it) hasnt. Have we(you,they) studied? Yes, you (we,they) have. No,you (we,they) havent. (2)动词的过去分词：规则与不规则 你还记得过去式吗？ 你能写出下列单词的过去分词吗？ be- finish- live- invite- see- paint- -help- like- tell- study- stop- hate- make- lugh- learn- play- write- say- Have- 请用两个单词分别写现在完成时的肯定句 ，否定句和疑问句。 I have written my postcard. I havent written my postcard. Have you written your postcard? Yes, I have. / No,I havent 你写对了吗？ 练一练 用完成时完成下列句子 1。The room is cold。Who（ open）the window？ 2。He（go）to the cinema。 3。you（put）away my dictionary? 4.We_(not finish) the work yet. 5.I_(see) the play. I _(see) it last month with my sister. 6.I am not hungry.I _just_(have) my dinner. (3) 用法 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。例如：I have opened the window.我已经把窗户打 开了。（窗户是开着的）The concert has started.音乐会已经开始（ 音乐会现在在进行）They have gone to Shanghai.他们已去上海了 （他们不在这里） 现在完成时不能和表示过去的时间状语， 如yesterday,last year,in 1980,three days agoJust now,when I came in等连用。但可以和一 些不确定的时间状语，如already,yetSometimes,often,before,lately,once,never,Just,ever 等连用；也可以和包括现在在内 的时间状语，如this morning, today, thisWeek, this year等连用。例如 She has already come.她已经来了。 I havent read it yet.我还没有读过这个 Have you ever seen each other before?你们 见过面吗？ 1.Dont worry. The train_yet.A.arrived B.wont arrive C.hasnt arrived2. B.表示过去已经开始、持续到现在（也许 还会继续进行下去）动作或状态，常和 表示一段时间状语，如:today, these days, since,for,this month,now等连用 。例如:I have studied English for two years.我学英语已经两年了。They have lived in Beijing since 1980.他们自年就一直住在北京。Weve known each other since we were children.我们从小就认识。注意：英语的行为动词大体可以分为两大类 型：一是延续性的动词，二是终止性动词。延续 行动词是指那些动作意义不会一下完成，而是可 以延续、发展的动词。如：work,read,write,study 等。这些动词的完成时可以和段时间状语连用。 终止性动词是指那些动作一次完成，不能延续的 动词。如：come, go, buy, die, join, begin等。这 些动词的肯定式不能和段时间状语连用。在用 法中要用延续性动词代替终止性动词。 She has been back for two years.(正）She has come back for two years（误）。终止性动词完成时的否定式表示一种否定状态是可 以延续的，所以其否定式可以和段时间状语连用 。 如：I havent seen him for ages.我好久没见到他 了。（现在仍没见到他）