2017人教版八年级下英语现在完成时语法讲解.doc

现在完成时（I）语法知识 定义：（1）表示过去发生或已经发生的动作对现在造成的影响或结果,这个影响和结果对现在还必须存在.常与already(已经), yet(已经,还), just(刚刚),ever(曾经)，never等词连用. already: 常用于肯定句或疑问句（均表示：已经）. yet: 常用于否定句(表示：还、尚),疑问句末尾（表示：已经）. 现在完成时的构成及句型结构：（注：过去分词的变化分规则变化与不规则变化，规则变化与动词原形变过去式一样，不规则变化见教材137页） 1.肯定句：主语+have/has+过去分词 +其他+时间. eg: I have already lost the key. 我已经弄丢了钥匙. (我现在没有钥匙) He has ever read that book . 他曾经看过这本书. (了解书的内容) They have just cleaned their hands. 他们刚刚洗过手了. (手是干净的) 2.否定句：主语+haven’t/ hasn’t+过去分词+其他+时间. eg: I haven’t lost the key yet. He hasn’t ever read that book . They haven’t just cleaned their hands. 3.一般疑问句：Have/Has+主语+过去分词+其他+时间？ 肯定回答：Yes, 主语+have/ has. 否定回答：No, 主语+haven’t/hasn’t. eg: Have you already lost the key? Yes, I have. No, I haven’t. Has he ever read the book? Yes, he has. No, he hasn’t. Have they just cleaned their hands? Yes, they have. No, they haven’t. 4.特殊疑问句：特殊疑问词+have/has+主语+过去分词+其他+时间？ eg: What have you already done? （done是do/does的过去分词） What has he ever done? What have they just done? 定义：(2)现在完成时表示从过去开始一直持续到现在还有可能继续持续下去的动作或状态。常与for, since引导的时间短语或从句连用. for+表示一段时间的词组； since+过去某一时间点的词组或一般过去式的句子. eg: She has learned English for 5 years. （她已经学习五年英语了） 解释：一直在学，持续了五年，并且还可能持续学下去. He has lived in Beijing since he was born . （自从他出生以后就居住在北京） 解释：从出生后就一直住在北京，持续到现在，还有可能一直住下去） Have you stayed here since 3 o’clock? （自从3点后你就一直呆在这儿吗？） 例题：选用for和since填空: 1. We haven’t seen each other ___ a long time. 2. His father has been in the factory ____ 10 years ago. 3. The film has been on ____ 20 minutes. 4. Mr. Green has worked here _____ he came to China. 5. His grandparents have been dead _____ several years. 6. It’s five years ______ we met last time. 7.I have already had dinner. （否定） I _______ _______ dinner _______. 8. Mum has cooked the dinner. Mum _______ ________ the dinner. 9. Susan has learned English at school. Susan________ ________English at