人教版八年级英语下册Have you read Treasure Island yet现在完成时.pptx

Unit 8Have you read Treasure Island yet?Section A Grammar Focus现在完成时态Present Perfect Tense现在完成时用法1. 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。 e.g. –Have you had your lunch yet? –Yes, I have. I’ve just had it. (现在 我不饿了。)2. 表示动作或状态从过去某一时刻开始，一直延续到现在，而且可能还要继续下去。现在完成时●现在完成时的构成:现在完成时是由“助动词have / has + 动词的过去分词”构成。助动词要和主语的人称、数保持一致。 一、过去式和过去分词的变化相同规则变化：1. 一般在动词词尾直接加ed。如： pick → picked → picked; wish → wished → wished; stay → stayed → stayed2. 以不发音的e结尾的动词后面加d。如：like → liked → liked; hope → hoped → hoped; phone → phoned → phoned3. 以“辅音字母 + y”结尾的动词，变y为i，再加-ed。如： study → studied → studied; hurry → hurried → hurried; reply → replied → replied4. 词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stop → stopped → stopped; clap → clapped → clapped不规则变化：5. 以不变应万变。如： let → let → let; put → put → put; read → read → read6. 若中间有双写e，则去掉一个e，单词末尾再加t。如： feel → felt → felt; keep → kept → kept; sleep → slept → slept7. 结尾的字母d变t。如： lend → lent → lent; build → built → built; send → sent → sent8. 变为以-ought或-aught结尾。如： buy → bought → bought; bring → brought → brought; catch → caught → caught; teach → taught → taught●现在完成时的用法:一.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I have already read Treasure Island.I have returned the book to the library.I have bought a new house.We haven’t finished our homework yet.?Have you finished doing your homework yet?●现在完成时的时间状语: (1) 用副词already和yet。already一般用于肯定句中, yet一般用于否定句和疑问句中。We have already finished our homework.(2) 用ever和never。多用于否定或疑问句中,表示“曾经”或“从未”等。 —Have you ever been to the Great Wall? 你曾经去过长城吗？ —No, I have never been to the Great Wall. 不, 我从未去过长城。 No, never. 不， 从来没有。●现在完成时的时间状语: (3) 用副词just（刚刚）和before。I have just finished my homework.They have never visited the Great Wall before..?Have you ever been to Hong Kong before?(4) 用表示到说话为止的过去时间状语, 如so far/up to now, in the past/ last few years等。So far we have learned seven unitsDeqing has changed a lot in the past / last few years.二. 表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止,也可能仍然在进行。常带有for和since等表示一段时间的状语。 ( 1).for+表示一段时间的短语 ( 2).since+表示过去时间点的词语 ( 3).since+表示过