防辐射服评测have的过去分词
had
现在完成时have/has +过去分词
基本格式
I / You / We / They + have + 过去分词 …
He / She / It + has +过去分词 …
否定式：在have/has的后面直接+not，
缩写为：hasn’t/ haven’t +过去分词
现在完成时的用法：
1. 未完成用法：表示过去的动作或状态持续到现在，并且有可能继续持续下去，也有可能到此结束，在这种用法中，谓语动词必须是持续性动词；
e.g. He has waited for his girlfriend in the restaurant for 3 hours.
他在餐厅等他的女朋友等了三小时了。（表示他从过去到现在这3小时一直在等待，且有可能继续等待。）
2. 已完成用法：表示过去发生的动作已经完成，但是对现在有影响。
e.g. I have lost my keys.
我把钥匙弄丢了。（表示“钥匙弄丢了”这个动作发生在过去，已经完成，但是对现在有影响。）
注：现在完成时经常与for, since, already, recently, so far, ever, never…之类的词语连用，具体分析见中高级语法内容。
@动词的过去分词形式@
现在完成时中的谓语动词结构为have/has + 过去分词，其变形（动词原形-过去式-过去分词）如下：
1. 规则变法：动词原形+ed，如：
start – started – started
clean – cleaned – cleaned
2. 不规则变法:
go – went – gone have – had – had
be – was/were – been do – did – done
run – ran – run fall – fell – fallen
3. 以-y结尾的动词，-y前面是辅音，改-y为-ied：
study – studied – studied
tidy – tidied – tidied
4. 以-e结尾的动词，直接后面加-d即可：
dance – danced – danced
dive – dived – dived
例 句
1. She has been a teacher for almost 20 years.
她当老师已经近20年了。
2. Mr. Johnson has lived in Beijing since 2000.
约翰逊先生从2000年就住在北京。
3. I haven’t read this book.
我没有读过这本书。
4. I have been to London three times so far.
我已经去过伦敦三次了。
5. We haven’t finished the project yet.
我们还没有完成这个项目。
练 习
根据题意，用动词的正确形式填空。
1. His father (work) in this factory since 1990.
2. Do you want to take this book?
— No, thanks. I (have) one already.
3. She can’t play with the other kids, because she (finish) her homework yet.
4. I like Beijing very much. I (be) there twice so far.
5. I (see) Sara since last week. Do you know where she has been to?
答 案
1. has worked
2. have had
3. hasn’t finished
4. have been
5. haven’t seen
