新概念英语 第二册 Lesson4.ppt

Grammar ? 一、现在完成时的含义 ? ? : 一个动作发生在过去，已完成对现在有一定的影响。 Eg ： I have had breakfast. We have watched this film. ? ? ：动作发生在过去，持续到现在并有可能一直持续下去。 Eg ： We have learnt English for six years. They have been here since they were born. ? ? 强调一个动作重复的次数或者量的累积。 Eg ： She has read this book three times. You have learnt four lessons till now. past future 一般过去时 now have/has + 过去分词（过分） 原型 过去式 过去分词 AAA 型 read read read AAB 型 beat beat beaten ABA 型 run ran run ABB 型 buy bought bought ABC 型 begin began begun 二、现在完成时的结构 ? 1. 肯定式 ? 现在完成时由“助动词 have/has+ 过去分词”构 成；规则动词的过去分词的构成与动词过去式相 同，不规则动词的过去分词见不规则动词表； have 可缩写为 ve ， has 可缩写为 s 。 ? Theyve worked in the factory for ten years. ? 他们在这个工厂工作十年了。 ? Hes been there before 。 ? 他以前去过那儿。 2. 否定式 ? 现在完成时的否定式就是在 has/have 后加 not ， have not 可缩写为 havent ， has not 可缩写为 hasnt 。 ? I havent found my lost cat. ? 我还没有找到我丢失的猫。 ? She hasnt finished her homework yet. 她还没有完成她的家庭作业。 ? 3. 疑问式 ? 现在完成时的疑问式就是把助动词 has ， have 提到句首： ? — Have you been to Dalian? ? 你去过大连吗？ ? ? Has she received my letter? ? 她已经收到我的信了吗？ ? ? 句型转换 ( 每空一词 ) ? 1. I have been to Macau before. ( 改为否定句 ) I been to Macau before. ? 2. He has learned English for 5 years. ( 改为一般疑问句 ) learned English for 5 years? ? 3. I bought a new bike just now. ( 用 just 改写 ) I just a new bike. 三、现在完成时的时间状语 ? 1. 现在完成时与不明确的过去时间状语副词 before ， just ， already ， yet ， ever 等连用。 ? Eg ： I havent seen him before. ? 我以前没有见过他。 ? They have just done their homework. ? 他们刚做完作业。 2. 现在完成时与 for/since 等引导的持续性时间状语或 these days ， so far/till now 等包括“现在时间”在内的时间状语连用。 ? Eg ： I have known him for six years. ? 我认识他六年了。 ? The doctor has saved over two hundred peoples lives so far. ?