内容正文:
译林英语八下Unit1语法讲解及习题
现在完成时
一、语法讲解
1. 现在完成时的定义
现在完成时是连接过去与现在的时态,核心是体现过去动作和现在的关联,主要表达三种含义:
持续动作:过去发生的动作,一直持续到现在仍在进行
影响动作:过去发生的动作,对现在造成了具体影响或产生了结果
经历动作:到目前为止的人生经历,或某动作累计发生的次数
2. 现在完成时的结构
句式
结构
例句
肯定句
主语 + have/has + 动词过去分词
I have lived in Nanjing for 10 years.(我在南京住了10年了。)
She has finished her homework.(她已经做完作业了。)
否定句
主语 + have/has + not + 动词过去分词
I haven't visited Shenzhen before.(我以前从没去过深圳。)
He hasn't finished his work yet.(他还没完成他的工作。)
一般疑问句
Have/Has + 主语 + 动词过去分词?
—Have you been to Beijing?(你去过北京吗?)
—Yes, I have. / No, I haven't.(是的,我去过。/ 不,我没去过。)
特殊疑问句
疑问词 + have/has + 主语 + 动词过去分词?
How long have you lived here?(你在这里住了多久了?)
What has he done?(他做了什么?)
3. 现在完成时的时间标志词详解
时间标志词是判断现在完成时的核心依据,不同类别标志词的用法、位置有明确区分,以下是高频标志词的详细说明:
类别
标志词
用法说明
位置
例句
持续类
for + 时间段
表动作持续的时长,后接具体时间长度
句末
We have learned English for 5 years.(我们学英语已经5年了。)
since + 过去时间点/从句
表动作的起始时间,从句用一般过去时
句末
He has lived here since 2008.(他从2008年起就住在这里了。) She has taught since she graduated.(她从毕业起就一直教书。)
so far/up to now/until now
表“到目前为止”,强调动作从过去到现在的积累
句首/句末
So far, I have learned 1,000 words.(到目前为止,我已经学了1000个单词了。)
影响类
already
表“已经”,仅用于肯定句,强调动作提前完成
助动词与过去分词之间
I have already finished my homework.(我已经做完我的作业了。)
just
表“刚刚”,仅用于肯定句,强调动作刚结束
助动词与过去分词之间
He has just left the office.(他刚刚离开办公室。)
yet
表“还(未)”,仅用于否定句/疑问句
句末
Have you found your key yet?(你找到你的钥匙了吗?) I haven't finished yet.(我还没完成。)
经历类
ever
表“曾经”,仅用于疑问句,询问过往经历
助动词与过去分词之间
Have you ever been to Shenzhen?(你曾经去过深圳吗?)
never
表“从未”,仅用于否定句,表无相关经历
助动词与过去分词之间
I have never visited the Great Wall.(我从来没去过长城。)
before
表“以前”,泛指过往时间,无具体节点
句末
I have read this book before.(我以前读过这本书。)
once/twice/three times
表动作发生的具体次数,可与其他标志词连用
句末
He has been to Shanghai twice.(他去过上海两次。)
4. 过去分词的构成
现在完成时的核心是动词过去分词,分为规则变化和不规则变化,规则变化与过去式一致,不规则变化需单独记忆。
规则动词(与过去式变化一致)
动词形式
变化规则
例词
(原形→过去分词)
例句
一般动词
直接+ -ed
finish → finished
I have finished the work.(我已经完成了工作。)
以e结尾
直接+ -d
change → changed
The city has changed a lot.(这座城市已经变了很多。)
辅音字母+y结尾
变y为i,再+ -ed
carry → carried
She has carried the box for me.(她已经帮我搬了箱子。)
重读闭音节(辅+元+辅)
双写末尾辅音字母,再+ -ed
stop → stopped
He has stopped working.(他已经停止工作了。)
不规则动词(需特殊记忆)
本单元高频不规则动词变化(原形→过去分词):
go → gone(去)、see → seen(看见)、be → been(是)、fall → fallen(落下)、come → come(来)、leave → left(离开)、do → done(做)、find → found(找到)
例句:I have been to Beijing twice.(我去过北京两次。)/ She has gone to the shop.(她去商店了。)
5. 延续性动词与短暂性动词(本单元重难点)
现在完成时表持续动作(接for/since等标志词)时,必须用延续性动词,不能用短暂性动词(瞬间完成,无法持续)。需掌握常见的短暂性动词→延续性动词/短语的转换。
短暂性动词:表示瞬间完成、无法持续的动作(如leave, buy, borrow, join)
延续性动词:表示可以持续的动作或状态(如be away, have, keep, be a member of)
本单元高频转换表
短暂性动词
(原形)
延续性动词/短语
转换例句
leave(离开)
be away (from)(离开的状态)
My father left home three hours ago.(我爸爸三小时前离开了家。)→ My father has been away from home for three hours.(我爸爸离开家已经三小时了。)
buy(买)
have(拥有)
She bought the book yesterday.(她昨天买了这本书。)→ She has had the book for a day.(她拥有这本书已经一天了。)
borrow(借入)
keep(保留)
I borrowed the pen last week.(我上周借了这支笔。)→ I have kept the pen for a week.(我借这支笔已经一周了。)
join(加入)
be a member of / be in(成为……的一员)
He joined the club in 2020.(他2020年加入了这个俱乐部。)→ He has been a member of the club since 2020.(他从2020年起就是这个俱乐部的一员了。)
start/begin(开始)
be on(进行中)
The film started ten minutes ago.(电影十分钟前开始了。)→ The film has been on for ten minutes.(电影已经开始十分钟了。)
die(死亡)
be dead(死亡的状态)
His grandpa died in 2019.(他的爷爷2019年去世了。)→ His grandpa has been dead since 2019.(他的爷爷从2019年起就去世了。)
6. 易混结构:have been to / have gone to
本单元高频易混点,均为现在完成时结构,核心区别在于是否返回说话地:
结构
核心含义
适用场景
例句
have/has been to + 地点
去过某地,现在已返回
描述过往的旅行经历
I have been to Shanghai twice.(我去过上海两次,现在已经回来了。)
have/has gone to + 地点
去了某地,现在还未返回
描述人当前不在说话地的状态
He has gone to Shanghai.(他去上海了,现在还没回来。)
二、语法习题
(一)用所给动词的正确形式填空
1. Sunshine Town ___________(change) a lot over the years.
2. The government ___________just ___________(turn) part of the town centre into a new park.
3. Recently, the air in our town ___________(improve) a lot.
4. Some people in the countryside ___________already ___________(move) to new buildings.
5. Last year, the government ___________(build) an art museum.
6. I ___________(not visit) the museum yet.
7. My father ___________(work) in this company for over 17 years up to now.
8. ______ you ___________(find) your lost key yet?
9. They ___________(never be) to the Great Wall before.
10. So far, I ___________(learn) 1,000 English words.
(二)单项选择
1. —I’m sorry to keep you waiting.
—Oh, not at all. I ___________here for only a few minutes.
A. have been B. had been C. was D. will be
2. —______ you ___________your homework yet?
—Yes, I ___________it ten minutes ago.
A. Did; do; finished B. Have; done; have finished
C. Have; done; finished D. Will; do; finish
3. —Where is your father?
—He ___________to Shanghai. He ___________there twice.
A. has gone; has been B. has gone; has gone
C. has been; has gone D. has been; has been
4. She ___________this book for nearly three weeks.
A. has borrowed B. has lent C. has bought D. has kept
5. Great changes ___________in our hometown over the past 10 years.
A. have happen B. have taken place C. happened D. have been taken place
6.—How long have you ___________the bike?
—For two weeks.
A. bought B. had C. borrowed D. lent
7. I ___________my hometown for a long time. I really miss it!
A. left B. went away from C. have left D. have been away from
8. —______ have you lived in Nanjing?
—Since I was born.
A. How long B. How soon C. How often D. How far
9. He ___________in this school since he ___________to China.
A. taught; came B. has taught; came
C. taught; has come D. has taught; has come
10.—Have you ever ___________to Shenzhen?
—Yes, I ___________there last summer.
A. gone; went B. been; went C. been; have gone D. gone; have been
(三)按要求改写句子
1. I have finished my homework. (改为否定句)
_____________________________________________________________________
2. He has lived here for 5 years. (改为一般疑问句并作肯定回答)
_____________________________________________________________________
_____________________________________________________________________
3. They have visited the Great Wall. (对划线部分提问)
_____________________________________________________________________
4. She has kept the book for two weeks. (对划线部分提问)
_____________________________________________________________________
5. My father left home three hours ago. (用现在完成时改写)
_____________________________________________________________________
(四)完成句子
1. 我来这里已经有两个小时了。
I _________________ here for two hours.
2.他自从大学毕业就住在深圳。
He _________________ in Shenzhen since he _________________.
3.你曾经去过北京吗?
___________you ever _________________ Beijing?
4.我还没有完成我的报告。
I _________________ my report ______.
5.他们已经搬进了新房子。
They ___________already _________________ new houses.
(五)短文填空
Millie: I’ve just found out many things about Shenzhen from my uncle. He (1) ___________(live) there since he finished college.
Sandy: Really? What did he tell you?
Millie: He said there are a lot more jobs now in Shenzhen, and the living conditions are much better.
Sandy: That’s nice. Did he tell you anything else?
Millie: Yes. Transport (2) ___________also ___________(improve) a lot. People can get around easily thanks to excellent public transport.
Sandy: Wow. I hope one day I can visit Shenzhen. (3) ___________you ___________(be) to Shenzhen before?
Millie: No, I (4) ___________never ___________(visit) Shenzhen, but I plan to do so this summer holiday. You can join me!
Sandy: Great idea! I (5) ___________never ___________(travel) to a big city like Shenzhen. I’m really looking forward to it!
三、参考答案及解析
(一)用所给动词的正确形式填空
1. has changed(over the years是现在完成时标志,主语Sunshine Town为第三人称单数,用has)
2. has; turned(just是现在完成时标志,主语the government为单数,用has+过去分词)
3. has improved(recently是现在完成时标志,主语the air为单数,用has+improved)
4. have; moved(already是现在完成时标志,主语some people为复数,用have+过去分词)
5. built(last year是一般过去时标志,直接用build的过去式built)
6. haven't visited(yet是现在完成时标志,否定形式为have not+过去分词,缩写为haven't)
7. has worked(for over 17 years up to now是现在完成时标志,主语my father为单数,用has+worked)
8. Have; found(yet是现在完成时标志,一般疑问句将have提前,主语是you,用have+found)
9. have never been(never+before是现在完成时标志,主语they为复数,用have+been)
10. have learned(so far是现在完成时标志,主语I为第一人称,用have+learned)
(二)单项选择
1. A(for only a few minutes是持续类标志词,用现在完成时;be here是延续性表达,have been符合)
2. C(yet是现在完成时标志,第一空用Have done;ten minutes ago是一般过去时标志,第二空用finished)
3. A(爸爸不在说话地,用has gone to;去过两次已返回,用has been to,地点副词there省略to)
4. D(for nearly three weeks是持续类标志词,需用延续性动词;keep是延续性动词,borrow/lend/buy均为短暂性动词)
5. B(over the past 10 years是现在完成时标志;take place“发生”无被动形式,happen的过去分词为happened,A形式错误)
6. B(for two weeks是持续类标志词,需用延续性动词;have是延续性动词,buy/borrow/lend均为短暂性动词)
7. D(for a long time是持续类标志词,需用现在完成时+延续性动词;be away from是延续性短语,leave是短暂性动词)
8. A(答语Since I was born是时间起点,用how long“多久”提问;how soon问“多久后”,how often问频率,how far问距离)
9. B(since引导时间状语从句,从句用一般过去时came,主句用现在完成时has taught)
10. B(have ever been to表“曾经去过某地”;last summer是一般过去时标志,用went)
(三)按要求改写句子
1. I haven't finished my homework.(现在完成时否定句,直接在have后加not,缩写为haven't)
2. —Has he lived here for 5 years? —Yes, he has.(一般疑问句将has提前;肯定回答为Yes, 主语+has)
3. What have they done?(对动作visited the Great Wall提问,用what;现在完成时特殊疑问句,助动词have紧跟疑问词,用done代替划线动作)
4. How long has she kept the book?(对时间段for two weeks提问,用how long;主语she是第三人称单数,助动词用has)
5. My father has been away from home for three hours.(将短暂性动词left改为延续性短语be away from;主语是单数,用has been away from,时间状语换为for three hours)
(四)完成句子
1. have been(“来这里”的持续状态用be here,现在完成时主语I用have been)
2. has lived; graduated from college(since从句用一般过去时graduated from college;主句主语he是单数,用has lived)
3. Have; been to(“曾经去过某地”用Have sb. ever been to...,主语是you,助动词用Have)
4. haven't finished; yet(“还未完成”用现在完成时否定式haven't finished;yet用于否定句末)
5. have; moved into(already是现在完成时标志,主语they是复数,用have+moved into“搬进”)
(五)短文填空
1. has lived(since引导从句用一般过去时,主句用现在完成时;主语he是单数,用has lived)
2. has; improved(描述到目前为止交通的变化,用现在完成时;主语Transport是单数,用has improved)
3. Have; been(询问“是否去过某地”,用Have sb. been to...;主语是you,助动词用Have)
4. have; visited(never+before是现在完成时标志;主语I是第一人称,用have+visited)
5. have; travelled(never是现在完成时标志;主语I是第一人称,用have+travelled)
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