Unit 8 Have you read Treasure Island yet？现在完成时（教案）

现在完成时
难点：对现在完成时的用法的理解---对现在造成的影响或结果。
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。
e.g. I haven’t seen her these days.
I’ve known Bob for three years.
I’ve been at this school for over two years.
时间状语：already, yet, just, ever, never, before
构成：
现在完成时是由“助动词have / has+ 动词的过去分词”构成的，规则动
词的过去分词构成与过去式相同，不规则动词的过去分词则需逐个记忆。
动词的过去式的变化和过去分词的变化并不完全相同。我们对它们作了一个大致
的分类。 (注：例子中单词的变化顺序为：动词原形 → 动词的过去式 → 动
词的过去分词)
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 → stayed
2. 以不发音的e结尾的动词后面加d。如：
like → liked → liked; hope → hoped → hoped;
phone → phoned → phoned
3. 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 → replied
4. 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 → read
6. 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 → slept
7. 结尾的字母d变t。如：
lend → lent → lent; build → built → built; send → sent → sent
8. 变为以-ought或-aught结尾。如：
buy → bought → bought; catch → caught → caught;
bring → brought → brought; teach → taught → taught
句式
1. 肯定句：主语 + have / has + 过去分词 (+ 其他)
2. 否定句：主语 + have / has + not + 过去分词(+ 其他)
3. 一般疑问句：Have/ Has + 主语 + 过去分词(+ 其他)
4. 特殊疑问句：
1)特殊疑问词 (不是句子主语) + have / has + 主语+过去分词 (+ 其他)
2) 特殊疑问词(是句子主语)+have / has+ 过去分词(+ 其他)
already和yet都可以作为现在完成时的标志词，但它们的用法不同。
◆already一般用于肯定句中。如：
We have already cleaned up our classroom.
注意：already用于疑问句中时通常表示惊奇。如：
Have you finished your homework already I can’t believe it.
◆yet一般用于疑问句和否定句中。如：
Have you seen her yet
The bus hasn’t come yet.
活学活用
1. Write the forms of the past tense and past participle:
drink ______ ______ see ______ ______ find ______ ______
leave ______ ______ tell _____ ______
2. —Why is Mr. Yang still in the teachers’ office
—Maybe he ________ his work yet.
A. doesn’t finish B. hasn’t finished C. haven’t finished
中考链接
( ) 1. —Do you know the movie Lost in Thailand
—Yes. I ______ it twice. It’s funny.
A. saw B. see C. have seen D. will see
( ) 2. —Lunch —No, thanks. I__________.
A. will eat B. am eating C. have eaten
( ) 3. —Where is Tom We can’t find him anywhere.
— Perhaps he _____ home.
A. has come B. is going C. went D. was going