资源简介

(共23张PPT)
Unit 8
Making a Difference
第4课时 (Section A 4a-4d)
R·八年级下册
Presentation
Watch two videos and fill in the blanks.
I ______ ____ you _____ a thousand years.
have loved
for
We______ _____ each other
_____ we were nine or ten.
have known
since
present perfect tense
现在完成时
Lead in
、
She has been a volunteer at a nursing home since last August.
He has volunteered here since his summer holidays started.
I have been a volunteer here for a few months.
How long have you been a volunteer
我已经在这里当志愿者几个月了。
她从去年八月起就在一家养老院当志愿者了。
自从他的暑假开始，他就一直在这儿做志愿者。
、
Have you been to our animal shelter before No, I haven't. But one of my friends has volunteered here for a long time.
Has she ever done volunteer work Yes, she has. She has been a volunteer at a nursing home since last August.
How long have you been a volunteer I have been a volunteer here for
a few months.
How long has he worked as a volunteer at the museum He has volunteered here since
his summer holidays started.
Read the sentences. How are for and since used differently
一先找出现在完成时的结构，二找出for和since 的区别
4a
现在完成时的构成：
have/ has +过去分词（done）
for+时间段
since+时间点
、
Have you been to our animal shelter before No, I haven't. But one of my friends has volunteered here for a long time.
Has she ever done volunteer work Yes, she has. She has been a volunteer at a nursing home since last August.
How long have you been a volunteer I have been a volunteer here for a few months.
How long has he worked as a volunteer at the museum He has volunteered here since his summer holidays started.
Read the sentences again，translate these sentences
4a
你以前来过我们的动物收容所吗？
不，我没去过。但是我的一个朋友已经在这里做义工很久了。
她曾经做过义工吗？
是的，她做过。
自从去年8月以来，她就一直在一家养老院做义工。
你做志愿者多久了？
我已经成为一个志愿者几个月了。
他在博物馆做志愿者有多久了？
自从他的暑假开始，他就已经在这做志愿者工作了。
、
1. 表示过去发生或已完成的动作对现在造成的影响或结果；
现在完成时 | 1. 定义
Past
Present
Future
Judy has been the first bunny cop in Zootopia.
朱迪成为了动物城第一只兔子警察（动物城有了兔子警察）。
Judy has investigated this case for 24 hours.
目前为止，朱迪已经调查案件超过24小时了（从24小时前一直调查到现在）
I have worked here for 7 years. 我已经在这里工作7年了。(还会持续下去）
2. 表示过去已经开始并一直持续到现在，并有可能还会持续下去的动作或状态。
Revision复习
未完成用法
常和“since” 或 “for” 连用。
、
含for或since的现在完成时 | 未完成用法的句式
1）现在完成时+for+一段时间
例：我好久没有见到她了。
I haven’t seen her for a long time.
2）现在完成时+since+表示过去的时间点
例：自1984年以来，史密斯先生就在这里工作。
Mr. Smith has worked here since 1984.
3）现在完成时+since+从句
例：自上大学以来他学了大约5000个英语单词。
He has learned about 5000 English words since he went to college.
总结：
since + 过去时间点 “自从…”，用来说明动作的开始时间；
for + 时间段 “持续了…” ，用来说明动作延续的时间长度。
、
for和since现在完成时之间的转换
My sister has had her cell phone ____a month.
=My sister has had her cell phone _________________.
since a month ago
1. for+时间段
2. since①+过去的时间点
②+从句(一般过去时)
= since+时间段+ago
for
、
如何区分点时间和段时间呢？
7:30
five years
three minutes
2026
May 5
two months
时间点
时间段
时间段
时间点
时间点
时间段
时间点指的是具体的时间，比如1点、4月7日、2026年12月；
时间段指的是一段时间内，比如说三点到四点，中间这一个小时就是一段时间。
、
1._______ two years 2._______ two years ago
3._______ last month 4._______1999
5._______ yesterday 6._______4 o’clock
7._______ about 4 months 8. _______ she was a baby
9.________we were children 10. _______ six hours
for
since
since
for
since
since
since
since
since
for
for和since的练习
、
现在完成时态中带有for或since的句子，动词需为延续性动词。
延续性动词表示能持续一段时间的动作或表示状态的词。
常见的延续性动词有stay、have、live、teach、learn、work、study、know等；
非延续性动词表示短暂的动作，从开始到结束，几乎同时或在极短的时间里就完成，常见的非延续性动词(词组)有come、go、leave、start、die、finish、become、join、buy、get married等。
、
现在完成时态中带有for或since的句子，动词需为延续性动词。用法如下
延续性动词可以在现在完成时中与表示一段时间的状
语连用，如：
“for+一段时间”
“since+过去的时间点”
“since +一段时间+ago”
“since 引导的时间状语从句（一般过去时）”
◆ My sister has kept these postcards since she was five.
我妹妹从五岁起就留着这些明信片了。
、
Look at these sentences. Do you think they are right or wrong
1 I have bought this book for 3 years.
2 I have bought this book since 3 years ago.
3 He has died for three years.
非延续性动词表示的动作极其短暂，不能持续。因此，在现在完成时肯定句中不可与表示一段时间的状语连用，应改用延续性动词。
1 I have had this book for 3 years.
2 I have had this book since 3 years ago.
3 He has been dead for 3 years.
、
Look at these two sentences. Do you think they are right or wrong
1 I haven't heard from him for a year.
2 I haven't heard from him since March.
在现在完成时否定句中，因为非延续性动词的“非延续性” 被否定，成为可以延续的状态，因而可与表示一段时间的状语连用，说明某个动作一直没发生。
、
非延续性动词转换为延续性动词的方法：
将非延续性动词转化为“be+形容词或副词”，这样才能和时间段连用：
非延续性动词 延续性表达 非延续性动词 延续性表达 非延续性动词 延续性表达
begin / start （开始） be on go there （去那里） be there come back （回来） be back
come here （来这里） be here Open （开业） be open Close （关门） be closed
Die （死） be dead marry （结婚） be married Finish （结束） be over
go to bed （上床睡觉） be in bed leave （离开） be away return （回来） be back
get out （出去） be out fall asleep （入睡） be asleep lose （丢失） be lost
fall ill （生病） be ill get / arrive / reach （到达） be in/at join / become （参加，加入） be in / be a member of
、
Complete the sentences with the correct forms of the verbs in brackets and for or since.
4b
1. This college student enjoys volunteering for the army. She___________(teach) English to the soldiers_____three years.
2. I__________(be) a member of the Red Cross for six years.
I have made a lot of friends __________I joined the organization.
3. Mr Wu has taught in a primary school as a volunteer ________
two years now. __________he started working there, he
__________(help) many students.
4. The organization___________(train) over 6,000 volunteers
__________it began to offer classes three years ago.
has taught
for
since
have been
for
Since
since
has helped
has trained
、
I love being a volunteer! I____________(work) with a sports organization for almost three years now. Since I started, I ____________ (help) out at over ten different sports events. I ____________(make) many new friends and I ______ even _____(meet) many famous athletes. For example, I ______(meet) two national football players from Argentina last month. They were at a
stadium for a charity match. The stadium _______(be) so big that
they_______ (get) lost. I gave them directions and they________
(smile) and_________(thank) me warmly. I am proud to be
a volunteer.
Complete the passage with the correct forms of the verbs in brackets.
4c
have worked
have helped
have made
have
met
met
was
got
smiled
thanked
运动员
慈善机构
体育场
方向
热情地
骄傲的
、
Work in groups. Interview your groupmates using the questions below.
4d
How long have you
known your best friend / that girl / …
had your favourite toy / bag / …
lived in this town / your
neighbourhood / …
1
—How long have you known your best friend
—I have known my best friend for five years.
2
—How long have you had your favourite toy
—I have had my favourite toy for six months.
3
—How long have you lived in your neighbourhood
—I have lived in this neighbourhood since 2023.
、
1. Mr. Brown has had his TV ________ 15 years.
2. I’ve taken driving lessons _________ last month.
3. Tom has worked in the factory _______ he left school ten years ago.
4. My friends haven’t visited me _______ my birthday.
5. She hasn’t had a good cup of coffee _______2 years.
6. Tom has worn glasses _________ two years ago.
for
since
for
since
since
since
用since或for填空。
Practice
、
Practice
用所给单词的正确形式填空，完成短文。
I 1. __________（be）a volunteer at the Sunshine Community Center for over two years now. I first 2. _______（join）the program in September 2022, so I 3. ____________（work）here since I was a freshman in college.
My main duty is to help with the after-school tutoring project. I 4._________（meet）so many wonderful children. One of them, a boy named Leo, 5. _________（be）in my class since the project started. I 6. _____________（watch）him grow from a shy kid into a confident student. It’s amazing to see the progress.
The work isn’t always easy, but it is incredibly fulfilling. I 7.___（learn)more about patience and communication than I ever thought possible. So far, our team 8. _____________（organize）three charity sales and 9. ____ _（raise）
a significant amount of money for new books and supplies.
I 10. _________________（not regret）my decision to volunteer for a single day. This experience has already shaped who I am, and I plan to continue for as long as I can.
have been
joined
have worked
have met
has been
have watched
have learned
has organized
has raised
have not regretted
、
Goodbye
Thanks!
https://www.21cnjy.com/recruitment/home/fine

展开更多......

收起↑