(共8张PPT)
Unit 8 Have you read Treasure Island yet?
Section A
Grammars
人教新目标版英语八年级下册
情景导入
They are all classic. I have already read them.
现在完成时
新知讲解
1. 现在完成时的构成
现在完成时是由“助动词have/has+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须加强记忆。
arrive
arrived
arrived
do
did
done
意
注
在现在完成时的各种结构中，have，has均为助动词，无实际意义，只起构成时态的作用，不可省略。当主语是第三人称单数时助动词用has，其余人称一律用have。
He has eaten breakfast. I have eaten breakfast, too.
表示过去发生的事对现在造成的影响或结果
新知讲解
2. 现在完成时的句式
(1) 肯定句式：主语+have/has+过去分词…
She has already finished her homework.
(2) 否定句式：主语+haven’t /hasn’t +过去分词…
She hasn’t finished her homework yet.
(3) 一般疑问句：Have/ Has + 主语+过去分词…?
Has she finished her homework yet?
常用标志词为already，yet，just等；
already用于肯定句，yet用于否定句或疑问句
Yes, she has. No, she hasn’t.
典型习题
句型转换
1. Lin Feng has already left school. (改为否定句)
Lin Feng _________ _________ school __________.
2. I have already watered the plant. (改为一般疑问句)
_______ you _______ the plant yet?
hasn’t left
yet
Have watered
典型习题
单项选择
( ) 1. Have they finished their homework ______?
A. too B. yet C. already D. either
( ) 2. —I ______ an English-Chinese dictionary.
— When ______ you ______ it?
—Yesterday afternoon.
A. have bought; did; buy B. buy; do; buy
C. have bought; will; buy D. buy; have; buy
B
A
总结提升
现在完成时的构成
现在完成时的句式
现在完成时
再见！
