六年级英语上册 Unit 1 Public signs（1）课件 苏教牛津版

1.Present Perfect Tense2.Present Perfect Continuous TenseⅠ 、现在完成时 1. 现在完成时的构成 2. 现在完成时的用法Ⅱ 、现在完成进行时 1. 现在完成进行时的构成 2. 现在完成进行时的用法Ⅲ 、现在完成时和现在完成进行时的比较1. 现在完成时的构成：主动式 :have/has done被动式 :have/has been done1. 现在完成时•We ___________________(already open) the window. 过去的动作 : we opened the window. 对现在的影响 : The window is open.have already opened2. 现在完成时的用法•The boys are tired. They ________________ (just play) a ball game.过去的动作 : The boys played a ball game.对现在的影响 : The boys are tired. have just played现在完成时表示过去发生或已完成的动作，或某一动作对现在造成的影响或结果。通常与表示包括现在在内的时间副词 just, already, before, yet, never, ever, lately, recently 等状语连用。小结：现在完成时用法 1--- 已完成、影响性用法 already: 用于肯定句 ;yet: 用于否定和疑问句• Daniel __________ (live) in Beijing since he came to China.has lived pastfuturenowcamelivehas lived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。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： ① for 和 since ， ② so far, up to now, today, until/till…, this week (month, year) ③ during /over /in the past few years (weeks, months…) 现在完成时用法 2--- 未完成用法小结：Fill in the blanks:①. a. She has learnt English 3 years.b. She has learnt English 3 years ago.c. They have lived here _____1990.forsincesince② I (see) her so far.③ What _________________ (happen) to the USA in the past 35 years?haven’t seen has happenedSince 的补充用法A. 主句 +since+ 从句Great changes have taken place since you left.B. It is + 时间段 + since+ 从句• It is / has been two years since I left my hometown.b. It was /had been two years since I had left my hometown...