as because since和for的区别
原因状语从句一般由because, since, as, for引导?注意as,because,since和for的区别:
①如果原因是构成句子的最主要部分,一般用because。because引导的从句一般不放在句子的开头。例如:
I missed the train because I got up late.
注:对于以why开头的问句,一般只能用because引导的从句来回答。
②如果原因已为人们所知,或不如句子的其余部分重要,就用as或since、since比as稍微正式一些。as和since引导的从句一般放在句子的开头。例如:
As he was not well,I decided to go there without him.
Since this method doesn't work, let's try another.
③for表示所说的理由是一种补充说明,因此,for引导的从句可以放在括号里,而且for引导的从句一般不放在句子的开头。例如:
I decided to stop and have lunch, for I was feeling quite hungry.
because, for, since和as
这四个词作为连词，都有“因为”的意思，都可以用来作为一个动作或情况提供原因或理由，但它们在用法上有区别：
because是从属连词，接表示直接原因的从句，往往放在句末(有时也放在句首)，直接明白地说明因果关系。因此，在回答why的提问时或原句有just, only, not…but all等副词强调原因时必须用because.
for是并列连语。接表示间接原因的并列分句，所说的理由是一种补充。说明for引导的句子一般放在句尾。试比较：
He isn't here today because he is ill.因为他病了，所以他今天没有来。
He must be ill, for he isn't here.他今天没来，看来一定是生病了。
since和as是从属连词，说明的是已为人们所知和理由。since的语气比because弱，但比as强。since和as引导的从句一般放在句子的开头。
他因为忙，所以没来。
As I have a day off today, I'll write to you.
因为我今天有一天假，所以就给你写信。
此外，since也可以述说推断的理。如：
It must have rained, since the ground is wet.
一定下过雨，因为地是湿的.
because，since，as，for这些词在实际使用中都可以用做连词，当做“因为”、“由于”来讲，但要注意它们所表达意思的语气的顺序是be－cause，since，as，for，而且它们的具体用法还存在很大区别，我们千万不能混淆这四个词。
because表示“因为”，用来表示最直接的因果关系或是听话人所不知道的原因，它所表达的语气是这四个词中最为强烈的，它所引导的原因状语从句一般要放在主句之后。
还要注意两种情况也只能用because来回答：1、用why来提问的特殊疑问句的回答，只能用because；
2、在强调句中，只能用because。
例：1、He didn’t attend the meeting because he had too much work to do.
2、It is because it rained last week that they put off the match.
since在语气上仅次于be鄄cause，更加强调“既然”、“由于”，用来表示大家已然知道的事实。
例：Since we have no money,we can’t buy it.
as在语气上稍弱于since，不如since正式，而且经常用于口语。
例：As he wasn’t ready in time,we went without him.for是四个词当中表示“因为”、“由于”意思时语气最弱的一个，它实际只是对它前面的主句加以补充说明理由或推断原因，要用分号和前面的主句分开。
热身训练1、Why was he late for school?____he got up tool ate.
A、Because
B、Since
C、As
D、For
2、"Is David at school today？""No,he is at home____he has a bad cold."
A、because
B、since
C、as
D、for
3、It rained last night,___the ground is wet.
A.because
B.since
C.as
D.for
key：1、A2、A3、D
Because 多用于表示直接原因, 而 for 可以表示原因又可以用于提出说明, 语气比 because 轻得多。Because 引导的从句一般放在主句后, 有时也可放在主句前, 而 for 引导的句子只能放在后面。
because
[bi5kCz, bE5kCz, bi5kEz]
conj.
因为
John didn't attend the meeting because he was ill.
约翰没有出席会议, 因为他病了。
B-he is tired, he does not want to go with us.
因为他太疲劳所以他不想和我们一起去。
I criticized him, not because I hate him but because I love him.
我批评他不是因为我恨他而是因为我爱他。
because of
因为; 由于; 为了(I didn't go out because of rain. 因为下雨, 所以我没有出去。)【说明】在 reason is 的后面, 人们常用that 而不用 because 开头的从句。
for
[fE(r), fC:(r)]
prep.
a present for Mary
给玛丽的礼物
I've got a little present for your birthday.
我有一件小礼物送给你过生日。
I can do it for myself.
我自己能做这件事。
These investigations are not done for nothing.
这些调查工作自然不是白做的。
(2)
以…为目的地；开往；前往
We set off for London.
我们动身去伦敦。
(3)
在…时间
She's coming for Christmas.
她在圣诞节来。
(4)
代；替；代表
Red is for danger.
红色代表危险。
What do you want for a present?
你要什么样的东西作礼物?
(5)
为了
for existence
为了生存
"Did you come to Paris for the purpose of simple leisure, or for business purposes?" "你到巴黎来的目的纯粹是为了休闲,还是为了做生意?"
(6)
对于；关于
For him to forfeit his favourite hobby would be impossible.
要他放弃他所喜爱的业余爱好是不可能的。
I have no ear for music.
我对音乐外行。
For many of these families a college education was something new.
"对其中的许多家庭来说,大学教育是件新事物。"
(7)
因为
He's learning English for the fun of it.
他为了好玩才学习英语的。
for several reasons
因为种种原因
We bought this house with a much higher price than others just for its convenience. "我们买下这幢房子花的钱比其它房屋要贵得多,就是图的方便。"
For all his efforts, he didn't succeed.
他虽然竭尽全力还是没有成功。
"For all your explanations, I understand no better than before."
"尽管你作了解释,我还是不懂。"
(9)
以…为价钱；付出
a pen for 50 pence 50
便士一枝笔
(10)
以…的价格，值
He paid 50 pence for the book.
他付了50便士买这本书。
(11)
经过（时间、距离）
We ran for two miles.
我们跑了两英里。
He stayed for a week.
他待了一周。
We haven't seen each other for ages.
我们好久没见面了。
(12)
用于for + 名词或代词 + to + 不定式动词的名词短语中
The bell rang for the lesson to begin.
开始上课的铃响了。
for example
例如
You can buy fruit here — oranges and bananas, for example.
你可以在这里买水果，例如买柑橘和香蕉。
"The government has reduced spending in several areas, for example in the construction of highways."
"政府已经在几个方面削减了开支,例如高速公路的建设。"
That's for you!
就是这样！
There's ... for you!
恰好相反
He just grabbed the money and left — There's gratitude for you!
他抓了钱就走，你可真会感激人！
KK: []
DJ: []
ad.(常用于现在完成时或过去完成时)
1. 此后;从那时到现在
She left school three years ago and has worked as a nurse ever since. 她三年前毕业,从那时起便一直当护士。
2. 之前,以前
prep.
1. (常用于现在完成时或过去完成时)自...以来,从...至今
I haven't heard from him since last year.
我自去年以来未曾收到过他的信。
conj.
1. (常用于现在完成时或过去完成时)自...以来,从...至今
It's been ten years since they married.
他们结婚到现在已经十年了。
She has been living a hard life since her husband died.
她自从丈夫死后,一直过着艰苦的生活。
2. 既然;因为,由于
He must have taken the book since it isn't here.
他一定是把书拿走了,因为书已不在这里了。
Since it is so hot, let's go swimming.
既然天气这么热,我们去游泳吧。
as
as 1
AHD:[2z] […z ] 非重读时
D.J.[#z][*z ]非重读时
K.K.[#z][*z ]非重读时
adv.（副词）
(1)
To the same extent or degree; equally:
同等地，一样地：同一限度或程度地；同等地：
The child sang as sweetly as a nightingale.
这孩子歌唱得同夜莺般婉转
(2)
For instance:
例如：
large carnivores, as the bear or lion.
大的食肉动物，如熊或狮子
(3)
When taken into consideration in a specified relation or form:
this definition as distinguished from the second one.
这个定义与第二个有区别
conj.（连接词）
(1)
To the same degree or quantity that. Often used as a correlative after so or as :
像，如同：同等的程度或量，常用作关联词后置于so 或 as ：
You are as sweet as sugar. The situation is not so bad as you suggest.
你甜如蜜。情形不如你说的那样糟
(2)
In the same manner or way that:
以同样方式，以同样方法：
Think as I think.
像我这样去想
(3)
At the same time that; while:
同时；当…时：
slipped on the ice as I ran home.
我跑回家时在冰上滑了一跤
(4)
For the reason that; because:
由于；因为：
went to bed early, as I was exhausted.
睡得早，因为我精疲力尽了
(5)
With the result that:
结果：
He was so foolish as to lie.
他太傻才会撒谎
(6)
Though:
尽管：
Great as the author was, he proved a bad model. Ridiculous as it seems, the tale is true.
这位作者尽管了不起，到头来却成了一个坏榜样。这个故事看似荒唐，却是真的
(7)
In accordance with which or with the way in which:
根据或按照这一方法：
The hotel is quite comfortable as such establishments go. The sun is hot, as everyone knows. 就设备而言，这个旅馆相当舒适。太阳非常热，这一点众所周知
(8)
Informal That:
【非正式用语】相当于that：
I don't know as I can answer your question.
我不知道能否回答你的问题
pron.（代词）
(1)
that；which；who。用在same 或 such 后：
I received the same grade as you did.
我和你得分一样
(2)
Chiefly Upper Southern U.S. Who, whom, which, or that:
【多用于美国中南部】 who，whom，which或that：
Those as want to can come with me.
想去的可以和我同去
prep.（介词）
(1)
In the role, capacity, or function of:
以…的身份，作为：充当角色、身份或功能的：
acting as a mediator.
充当调解人
(2)
In a manner similar to; the same as:
以相似的方式；如同：
On this issue they thought as one.
在这个问题上，他们意见一致
习惯用语
--------------------------------------------------------------------------------
as is【非正式用语】
Just the way it is, with no changes or modifications:
按现状：就用这种方式，不加改变或修饰：
bought the samovar as is from an antique dealer.
原封不动地从古董商那里买到这套俄国式茶具
as it were
In a manner of speaking; as if such were so.
以说的方式；似乎如此
as is
按现状（出售），概不保证（维修）
as it were
或者说
He is my best friend, my second self, as it were.
他是我最好的朋友，或者说，是第二个我。
as of right
依照法律
as if
好像，好似
She spoke to me as if she knew me.
她和我说话的神情，好像她早就认识我似的。
(= as though)
as long as
只要
You may borrow this book as long as you promise to give it back. 只要你答应归还，你就可以把这书借走。
(= so long as)
as of
自从；自…起
as of today
从今天起
(= as from)
as oppesed to
与…不同；与…相反
as though
好像，好似
as to
关于；至于
I don't know anything as to the others.
至于其他，我一无所知。
so As not to
以便不, 免得
so As to
这(那)样...以致
so long As
只要
so much As
连...都不
As above
如上, 同上
As against
与...比较; 比起...来
As... As any
不亚于任何一个; 不比别的差
As ... As anything
极为; 非常
As ... As ... can be
到了...的程度; 极其...
As ... As ever
(1)
永远; 依旧, 仍然
(2)
自古; 至今; 空前 (He is As brilliant a politician As ever lived. 他是古今最卓越的政治家。)
(3)
[与one 或you can 连用时]尽可能地; 越...越好(Be As quick As ever you can. 越快越好)
As for
至于; 就...方面说来
As from
从...时起(公文用语)
As if
好象...似的; 仿佛...一样
As though
好象...似的; 仿佛...一样
As is
[口]照原来的样子; 不予改变; 本来就是这样
As it is
事实上, 实际上; 照现在的样子
As they are
事实上, 实际上; 照现在的样子
As it were
仿佛, 好象, 可以说
As many (much) As
As of
在...时; 到...时为止; 从...时起
As to
(1)
谈到; 关于
(2)
至于
As well
(1)
倒不如, 还是...的好; 最好...还是(It will be As well to stop that young screamer. 但是最好还是让那个大哭大叫的孩子住声。)
(2)
同样; 也
As well As
也; 又
As well ... As not
反正都行; 都一个样(You may As well go there As not. 你去不去都行。)
As yet
[多用于否定句中]到现在为止; 到那时为止
A-you were!
【军】[口令]复原!
介词讲解,练习题及答案
四：介词 介词又叫前置词，是一种虚词。介词分为三种，一种是简单介词，如at, in, on, beside, to , for 等；另一种是短语介词，即由两个以上的词组组成的短语，如in front of, because of, out of, instead of等；还有一种叫二重介词，如until after, from behind等。 （一）介词的句法功能 介词不能独立在句中做成份，介词后必须与名词、代词、或动名词构成介词短语在句中充当一个成份，表示人、物、事件等与其它人、物、事件等之间的关系。 1、作定语：The book on the table is mine. 2、作状语：We have breakfast at seven.（表时间）；They were late for meeting because of the heavy rain.（表原因）；They started the machine by pressing the button.（表方法） 3、作表语：My dictionary is in the bag. 4、作宾语补足语：I found him in the office. （二）主要介词区别 1、表示时间的at, in, on：at表示片刻的时间，如：at 8 o’clock ，常用词组有：at noon, at night, at midnight, at the end of, at that time, at the beginning of, at the age of, at Christmas, at New Year等。in表示一段的时间，如：in the morning, in the afternoon, in the evening, in October, in 1998, in summer, in the past, in the future等。on总是跟日子有关，on Monday, on Christmas morning, on the following, on May Day, on a warm morning等。 2、表示时间的since和from：since表示从过去到现在的一段时间的过程，常与现在完成时连用。from表示从时间的某一点开始，不涉及与现在的关系。一般多与现在时、过去时、将来时连用。如：I hope to do morning exercises from today./ We have not seen each other since 1995. 3、表示时间的in和after：两者都表示“在（某个时间）之后，区别在于in表示“在（一段时间）之后”，而after则表示“在（某一具体时间点之后）”，in短语和将来时态连用，after 短语和过去时态或将来时态连用。如：We’ll be back in three days./ After seven the rain began to fall./ What shall we do after graduation? 注意：after有时也可以表示在一段时间之后（常用在过去时里）。如：After two months he returned. 4、表示地理位置的in, on, to：in表示在某范围内，on指与什么毗邻，to指在某环境范围之外。如：Changchun is in the northeast of China./ Mongolia is on the north of China./ Japan is to the east of China. 5、表示“在……上”的on和in：on只表示在某物的表面上，而用in表示占去某物一部分。如：There is a book on the piece of paper./ There is an interesting article in the newspaper./ He dug a hole in the wall. 6、表示“穿过……”的through和across：through表示从内部通过，与in 有关；across则表示从一端至另一端在表面上的通过，与on有关。如：Water flows through the pipe./ The old man walked across the street. 7、in the corner, on the corner, at the corner：in the corner 表示在角落里，in指角的内面；on the corner表示“在角上”，on指的不是内面，也不是外面，而含内外兼有之意；at the corner 指“在拐角处”，at指的是拐角外附近的外面。如：The lamp stands in the corner of the room./ I met with him at the street corner./ He sat on the corner of the table. 8、in the end, at the end of, by the end of：in the end作“最后”、“终于”解，可单独使用，后不接介词of；at the end of 表示“在……末梢”，“到……尽头”，既可指时间，也可以指地上或物体。不可单独使用；by the end of 作“在……结束时”，“到……末为止”解，只能指时间。不
人教版英语八年级下册试题since 和 for 的用法(用于现在完成时)
初中英语学习材料 madeofjingetieji since 和for 的用法(用于现在完成时) 表示过去已经开始持续到现在的动作或状态常用的时间状语有：for, since, how long, so far, these days等。 1. since : a).since +时间点①年代②时刻数③一段时间+ago b).现在完成时：主句(主语+have/has +延续性动词的过去分词)+ since +从句一般过去时 c) It’s +时间段+since +短暂性动词的过去式 d).时间段+has passed +since +短暂性动词的过去式 for +一段时间 练习： 用since和for填空 1) ______ two years 2) _______ two years ago 3) _______ last month 4) ______ 1999 5) _______ yesterday 6) _______ 4 o’clock 7) ______ 4 hours 8) _______ an hour ago 9) _______ we were children 10) _____ lunch time 11) ______ she left here 12). He has lived in Nanjing ________ the year before last. 13). I’ve known him __________ we were children. 14). Our teacher has studied Japanese _________ three years. 15). She has been away from the city ___________ about ten years. 16). It’s about ten years __________ she left the city. 2. for: for +一段时间= since +一段时间+ ago 3. 与时间段连用时，短暂性动词应改为相应的延续性动词。 1) come/go to ------ be at /in 2)leave ----be away from 3)buy ----have 4) borrow /lend -----keep 4)open ---be open 5)close---be closed 6) die---be dead 7) start/begin ----be on 8) join—--be in /be a member of /be a soldier 9) become –be 10) fall asleep ---be asleep 11)catch a cold – have a cold 12) have/has gone to → have been in 13) put on → wear14) finish/end → be over 15) marry → be married 练习：.短暂性转换延续性 1) His grandfather died two years ago . His grandfather has ____ ____ for two years. _____two years _____ his grandfather ____. Two years ____ ____ ____ his grandfather _____. 2) I became a teacher in 2000. I ________ __________ a teacher for _________ _________. 3) The shop closed two hours ago. The shop ________ _________ _________ for _________ _________. 4) The door opened at six in the morning. The door ________ ________ ________ for six hours. 5)He left Fuzhou just now. He _______ ________ ________ _________ Fuzhou for five minutes. 6)The film began two minutes ago. The film ____ ____ ____ for ____ ____.How time flies! 7)They borrowed it last week. They _________ _________ it since __________ __________. 8)I bought a pen two hours ago. I _________ _________ a pen for ________ __________. 9)They married in 1990. They ________ _________ __________since _________. 10)The meeting finished at six. The meeting ________ ______ ______ for six hours. 11)My brother joined the army two years ago.
because,since,as,for的用法区别
because、since、as、for的用法区别 because、since、as、for这几个词都是表示“原因”的连词，语气由强至弱依次为：because→since→as→for。其中because、since和as均为从属连词，引导原因状语从句；而for是并列连词，引导并列句。 ?because because表示直接原因，它所指的原因通常是听话人所不知道的，其语气最强。常用来回答why的提问，一般放在主句之后，也可以单独存在例如： (1)Istayed at home because it rained. 因为下雨，我呆在家里。 (2)B ecause Lingling was ill, she didn’t come to school. 玲玲因为生病，没有上学。 (3)—Why is she absent? 她为什么缺席? —Because she is sick. 因为她病了。 (4)此外，在强调句型中只能用because。例如， It was because I missed the early bus that I was late for school. 我上学迟到是因为我错过了早班车。 ?since since侧重主句，从句表示显然的或已为人所知的理由，常译为“因为、既然”，语气比because稍弱，通常置于句首，表示一种含有勉强语气的原因。例如： (1)Si nce he asks you, you’ll tell him why. 他既然问你了，那就告诉他为什么吧。 (2)Si nce everyone is here, let’s start. 既然大家都到齐了，我们就是出发吧。 (3)Since I understood very little Japanese, I c ouldn’t follow the conversation. 我日语懂得不多，因而听不懂对话。 ?as as是常用词，它表示的“原因”是双方已知的事实或显而易见的原因，由于理由不是很重要，含义与since相同，但语气更弱，没有since正式，常译为“由于，鉴于”。从句说明原因，主句说明结果，主从并重。例如：
英语介词练习题含答案
英语介词练习题含答案 一、初中英语介词 1．Look at the picture on the right! She is going _______. A. into the library B. out of the post office C. into the supermarket 【答案】C 【解析】【分析】句意：看右边的图画！她要去超级市场。A. into the library进图书馆；B. out of the post office走出邮局；C. into the supermarket进超市。根据右边的图片可以看到这名妇女正要走进超市，结合选项，故答案为C。 【点评】考查图片辨析。看懂图片，理解题意，注意熟记表示地点的名词。 2．I'll be at home __________ Sunday morning. You can phone me then. A. on B. in C. at D. to 【答案】 A 【解析】【分析】句意：在周日早上我将在家，那时你可以给我打电话。on+具体时间；in+the+morning/afternoon/evening，在早上/下午/晚上；at+时间点。Sunday morning指的是周日早上，指的是具体日期，所以用on，故选A。 【点评】考查介词辨析，注意平时识记on、in、at的区别。 3．John often takes a walk _______ his grandpa after dinner. A. to B. for C. along D. with 【答案】 D 【解析】【分析】句意：约翰经常晚饭后和他的爷爷散步。A.朝；B.为了；C.沿着；D.和……一起。根据his grandpa，可知此处应是晚饭后跟爷爷散步，故选D。 【点评】考查介词辨析。注意句子涉及到with的词义和用法。 4．Humans can not make progress dreams. A. with B. without C. through D. about 【答案】 B 【解析】【分析】句意：没有了梦想，人类就不会进步。A.带着，有；B.没有；C.通过；D.关于。梦想是人类前进的动力，根据Humans can not make progress，可知人类不会进步，是因为没有梦想，应会使用介词without，故答案是B。 【点评】考查近词辨析，注意识记介词without的用法。 5． , I found the job boring, but soon I got used to it.
中考英语：since与for用法
现在完成时态中的since 与for 1. 实例： We have studied English for more than 2 years. 我们学英语已有两年多时间了。 She has been ill since last Sunday. 她从上周星期天一直病到现在。 2. 用法说明： (1) 介词for 短语表示一个时间段，指某个动作或情况到现在为止已持续了多久，提问时用how long；since 作为介词，接一个时间名词，作为连词，引导一个时间状语从句(从句动词一般是短暂性动词)，since 表示“自…以来”，指某个动作或情况从过去某一点时间一直持续到现在，因此，与for 或since 引出的时间状语连用的句子(或主语)谓语动词必须是持续性的(如上面两句中的动词study 和be) (2) 英语中有些动词的意义不能持续，表示的是一瞬间就结束的动作，这些动词被称为非持续性动词或短暂性动词，常见的如come, leave, go, lose, see, begin, start, arrive, bec ome, die, buy, borrow, close, join, reach, fall, get up 等。这类动词可以用于完成时态，但在肯定句中不能与表示动作延续的时间状语for 或since 短语连用。如：正：He has come back. 他已回来。 误：He has come back for three days. 若要表示“他回来已三天了”这样的意思，可以将动词改为延续性动词，或改变时间状语，或改用别的句型等，如译为： He has been back for three days. (改变谓语动词) He has been back since three days ago. (改变谓语动词) He came back three days ago. (改变时间状语及动词时态) It’s three days since he came back. (改变句型) (3) 非持续性动词用于完成时态，在肯定句中不能与for 或since引出的短语(或句子)连用，但在否定句中是可以的，因为一个非延续性动词一旦被否定即成为状态，而状态总是可以延续的。如：(https://www.360docs.net/doc/f317430057.html,) I haven’t seen him for a long time. 我很久没见到他了。 He hasn’t come here for some time. 他有段时间没来了。 I haven’t heard from her since she left. 自他离开以后，我一直没收到她的来信。
because because of since 练习
Unit 7 The unknown world 语法练习一．基础巩固。 ( )1. I hate travelling by air_____ you usually have to wait for hours before the plane takes off. A. because B. though C. until D. Unless ( )2. Because it is hot, _____ we decide to go swimming. --Can I join you? A. so B. thus C./ D. for ( )3.—Why you are absent? --_____ I am ill. A. Since B. For C. As D. Because ( )4.____ everyone is here, let’s begin. A. But B. Since C. So D. If ( )5.She was praised______ she often helped others. A. but B. for C. or D. if ( )6.______ the heavy snow, we didn’t go to school. A. Because B. Because of C. For D. Since ( )7.Because it is raining,_____ we have to put off the sports meeting. A. so B./ C. and D. then ( )8.--_______it is late , I should go home now. --Oh, do you have to? A. Since B. Or C. Because of D. But ( )9.—The sun must have set,____ it is growing dark. --- Yes, and it’s 6 o’clock now. A. for B./ C. however D. thus ( )10.--- I will go to the party alone ____ you don’t want to go. A. until B. since C. however D. whether ( )12. The man can’t get on the bus ______ there is no room on it. A. though B. because C. until D so that ( )13. ______ her daughter hadn’t come back, ______ she looked worried. A. Because, / B. Because, so C. Though, but D. Though, / ( )14._______ you’ve got a chance, you might make full use of it. A. Now that B. After C. Although D. As soon as ( )15. He found it difficult to read, _______ his eyesight was beginning to fail. A. and B. for C. but D. or ( )16. A man cannot smile like a child, ________ a child smiles with his eyes, while a man smiles with his lips alone. A. so B. but C. and D. For 形容词、副词综合复习与训练 ( )1．Water is the cheapest drink. And it's also ________. A．healthier B．healthiest C．the healthier D．the healthiest ( )2．—How do you feel about the movie？
现在完成时练习题及答案
一、时态讲解：现在完成时 （1）构成：现在完成时由助动词have + 过去分词构成，助动词have 有人称和数的变化。第三人称单数用has，其余用have. 现在完成时的否定式直接在助动词后面加上not、疑问式是把助动词have/has提到主语之前。以study 为例，其否定式、疑问式和简单回答形式如下： 1）现在完成时通常表示在说话之前已经完成的动作或存在的状态。说话人强调的是该动作或状态对现在的结果或影响。 My daughter has just gone out. 我女儿刚出去。 I’m sure we’ve met before. 我肯定我们以前见过面。 She has arrived. 她到了。 2）表示持续到现在的动作或状态，往往和包括现在在内的表示一段时间的状语连用，如recently, already, just, la tely, for…, since…,yet等。如： I haven’t heard from her these days. 这些日子我没有收到她的信。 We haven’t seen you recently. 最近我们没有见到你。 They have been away for two years. 他们离开已经两年了。 She has been with us since Monday. ★注意： a)since和for的区别 since后接时间点，如1993，last term, yesterday, the time I got there for后接一段时间，表示“长达多久”，如ten years, a while, two days等。 Exercise: 用since和for填空 1. Jim has been in Ireland ______ Monday. 2. Jill has been in Ireland ______ three days. 3. His aunt has lived in Australia ______15 days. 4. Mary is in her office. She has been there ______ 7 o'clock. 5. India has been an independent country ______1974. 6. The bus is late. They've been waiting ______ 20 minutes. 7. Nobody lives in those houses. They have been empty ______ many years. 8. Mike has been ill ______a long time. He has been in hospital ______ October. 1. since 2. for 3. for 4. since 5. since 6. for 7. for 8. since 2）表示短暂意义的动词如arrive, leave, borrow, buy, begin, start, die等，在完成时当中不能和表示一段时间的状语连用，因为它们表示的动作不可能持续。因此，不能说：
Since-和-for-的用法及区别
S i n c e-和-f o r-的用 法及区别 -CAL-FENGHAI-(2020YEAR-YICAI)_JINGBIAN
Since 和 for 的用法及区别： 一，since 的四种用法 1，since + 过去一个时间点（如具体的年、月、日期、钟点、ago. 1990 , last month , half past six I have been here since 1990. 1990起，我一直在这儿。 2，since+ 一段时间+ago I h a v e b e e n h e r e s i n c e f i v e m o n t h s a g o。自从五个月前，我已经在这儿了。 3，since+从句Great Changes have taken place since you left. 自从你走后，已经发生了很大的变化。 4，It is +一段时间+since从句 I t i s t w o y e a r s s i n c e I b e c a m e a n E n g l i s h t e a c h e r.我成为英语老师有两年了。 二，Since 和for区别 1，Since +时间点，具体时间 “自从、、、、以来，从、、、以后”用来说明动作起始时间 I have been in Beijing since 2010. 2，For + 时间段，用来说明动作延续时间长度，因此句中的谓语动词，也应该是延续性动词。 I have been in Beijing for one year。 We have learnt English for about three years. I have been here for 3 days. (对) I have arrived here for 3 days.（误） 三，延续性动词和终止性动词的概念 英语中，动词按其动作发生的方式、动作发生过程的长短，可分为延续性动词和终止性动词。 延续性动词 表示能够延续的动作，这种动作可以延续下去或产生持久影响。如：
现在完成时与完成进行时for和since练习题
现在完成时练习题 I. 用never, ever, already, yet, for, since填空 1.I have _______ seen him before, so I have no idea about him. 2.Jack has _________ finished his homework ________ an hour ago. 3.Mr. Wang has taught in this school ________ ten years. 4.“Have you ________ seen the film”“No, I have ________ seen it.” 5.“Has the bus left _______”“Yes, it has _________ left.” II. 用since和for填空 A. 1) ______ two years 2) _______ two years ago 3) _______ last month 4) ______ 1999 5) _______ yesterday 6) _______ 4 o’clock 7) ______ 4 hours 8) _______ an hour ago 9) _______ we were children 10) _____ lunch time 11) ______ she left here B. 1. He has lived in Nanjing ________ the year before last. 2. I’ve known him __________ we were children. 3. Our teacher has studied Japanese _________ three years. 4. She has been away from the city ___________ about ten years. 5. It’s about ten years __________ she left the city. 6. I've been practicing the piano since 10∶30. 7. Mario has been running ____ 15 minutes. 8. Sarah has been sleeping ____ 9∶00. 9. Dale has been talking on the phone ____ five minutes. 10. Louie has been studying Chinese ____ he was six years old. 11. I've been watching you ____ ten minutes. 12. She?has?done?her?homework?_________?two?hours. 13. Tom?has?been?swimming??_________?an?hour. 14. They?have?learnd?English?________?they?came?to?school. 15. They?have?been?in?the?room?__________8?o’clock. 16. We?have?studied?English?_________several?years. 17. I?have?been?living?in?Xi’an?_________I?was?born. 18. She?has?worked?here?_________?2006. 19. Mary?has?been?running?_________?she?came?here. 20.?Ann?has?been?learning?English?since?2003.（选出同义词组） A.?for?2003 B.?since?about?6?years? C.?6?years?ago D.?for?about?6?years III. 用过去时或现在完成时填空： 1. “_________ you __________ (write) a letter to your aunt yet” “Yes, I ___________. I ________________ (write) one last week.” 2. “_________ he ___________ (finish) his homework”“Not yet.” 3. “_________ they ever __________ (be) abroad”“Yes, just once.” 4. Your father _________ just ___________ (finish) his work. 5. Your father _________ (finish) his work just now. 6. Last term I __________ (learn) many English words. 7. They ____________ (not read) the interesting books yet.
as because for since用法区别
because, as, for, since这几个词都是表示“原因”的连词，语气由强至弱依次为： because→since→as→for;其中because, since, as均为从属连词，引导原因状语从句；而for 是并列连词，引导并列句。 1. because表示直接原因，它所指的原因通常是听话人所不知道的，其语气最强。常用来回答why的提问，一般放于主句之后，也可以单独存在。例如： (1)I stayed at home because it rained. 因为下雨我呆在家里。 (2)Because Lingling was ill, she didn”t come to school. 玲玲因病，没有上学。 (3)�Why is she absent? 她为什么缺席？ �Because she is sick. 因为她病了。 此外，在强调句型中，只能用because。例如： (4)It was because I missed the early bus that I was late for school. 我上学迟到是因为我没有赶上早班汽车。 2. since侧重主句，从句表示显然的或已为人所知的理由，常译为“因为”、“既然”，语气比because稍弱，通常置于句首，表示一种含有勉强语气的原因。例如： (1)Since he asks you, you”ll tell him why. 他既然问你，那就告诉他为什么吧。 (2)Since everyone is here, let”s start. 既然大家都到齐了，我们就出发吧！ (3)Since I understood very littl e Japanese, I couldn”t follow the conversation. 我日语懂得不多，因而听不懂对话。 3. as是常用词，它表示的“原因”是双方已知的事实或显而易见的原因，或者理由不是很重要，含义与since相同，但语气更弱，没有since正式，常译为“由于，鉴于”。从句说明原因，主句说明结果，主从并重。例如： (1)We all like her as she is kind. 我们都喜欢她，因为她善良。 (2)As I had a cold, I was absent from school. 因为我感冒了，所以没去上课。 (3)As Xiaowang was not ready, we went without him. 由于小王没有准备好，我们只好不带他去了。 4. for用作连词时，与because相似，但它所表示的原因往往提供上文未交待过的情况。for 不表示直接原因，表明附加或推断的理由，因此for被看作等立连词，它所引导的分句只能
现在完成时Since和for的用法
现在完成时Since和for的用法 Since 和for 的用法 表示过去已经开始持续到现在的动作或状态常用的时间状语有：for, since, how long, so far, these days等。 Since+过去点的时间，for+一段时间(数词+量词)，此划线部分用how long提问。 一、since短语或从句表示过去的动作延续至今，since之后的时间为一点。如： Mr. Smith has worked here since 1984. 1984年以来，史密斯先生一直在这工作。 He’s learned about 5,000 English words since he went to college. 他上大学以来大约学了五千个英语单词。 二、for短语表示动作延续多长时间，for的宾语为时间段。如： We have known each other for twenty years. 我们认识有二十年了。 I haven’t seen her for a long time. 我好久没有见到她了。 练习：用since和for填空 1) ______ two years 2) _______ two years ago 3) _______ last month 4) ______ 1999 5) _______ yesterday 6) _______ 4 o’clock 7) ______ 4 hours 8) _______ an hour ago 9) _______ we were children 10) _____ lunch time 11) ______ she left here 1. He has lived in Nanjing ________ the year before last. 2. I’ve known him __________ we were children. 3. Our teacher has studied Japanese _________ three years. 4. She has been away from the city ___________ about ten years. 5. It’s about ten years __________she left the city. 2.短暂性转换延续性
四因为as_because_for_since用法区别
“SI因为”because for as since because, as, for, since这几个词都是表示“原因”的连词，语气由强至弱依次为：because→since→as→for;其中because, since, as均为从属连词，引导原因状语从句；而for 是并列连词，引导并列句。 1. because表示直接原因，它所指的原因通常是听话人所不知道的，其语气最强。常用来回答why的提问，一般放于主句之后，也可以单独存在。例如： (1)I stayed at home because it rained. 因为下雨我呆在家里。 (2)Because Lingling was ill, she didn”t come to school. 玲玲因病，没有上学。 (3)——Why is she absent? 她为什么缺席？ ——Because she is sick. 因为她病了。 此外，在强调句型中，只能用because。例如： (4)It was because I missed the early bus that I was late for school. 我上学迟到是因为我没有赶上早班汽车。 2. since侧重主句，从句表示显然的或已为人所知的理由，常译为“因为”、“既然”，语气比because稍弱，通常置于句首，表示一种含有勉强语气的原因。例如： (1)Since he asks you, you”ll tell him why. 他既然问你，那就告诉他为什么吧。 (2)Since everyone is here, let”s start. 既然大家都到齐了，我们就出发吧！ (3)Since I understood very little Jap anese, I couldn”t follow the conversation. 我日语懂得不多，因而听不懂对话。 3. as是常用词，它表示的“原因”是双方已知的事实或显而易见的原因，或者理由不是很重要，含义与since相同，但语气更弱，没有since正式，常译为“由于，鉴于”。从句说明原因，主句说明结果，主从并重。例如：
英语人教版八年级下册since 和 for的用法
藤县第三中学微课设计模板（参考使用） 录制时间： 2016年6月15日微课时间：7.54分钟微课名称for 和 since的用法 知识点描述for 和 since 在现在完成时态中的用法 知识点来源学科：英语年级：八年级教材：人教版章节：第十单元页码： 73 □不是教学教材知识，自定义：是 基础知识听本微课之前需了解的知识： 现在完成时态的用法以及for和since定义和用法 教学类型√□讲授型□问答型√□启发型□讨论型√□演示型□联系型□实验型□表演型□自主学习型□合作学习型□探究学习型□其他 适用对象学生：本微课是针对本学科平时成绩多少分的学生？ □40分以下□40-60分□60-80分 √□80-100分□100-120分□120-150分 教师：□班主任□幼儿教师√□普通任课教师□其他其他：√□软件技术□生活经验□家教□其他 设计思路这是语法课，因此我用归纳法讲解，通过例子，然后总结，再比较，最后得出结论。 教学过程 内容画面时间 一、片头（20秒以内）内容：您好，这个 微课重点讲解辨 析for和since的 用法 第 1 至张PPT 2秒 二、正文讲解（4分20秒左 右）第一节内容：辨析 for和since的用 法 第 2 至11 张PPT 315 秒 第二节内容：典型 例子 第 12 至 14张PPT 116 秒
第三节内容：总结内容第 15 至张PPT 40 秒 三、结尾（20秒以内）内容：感谢大家能 认真的听完这个 微课，希望大家回 去后多做练习加 以巩固。 第 16至张PPT 1 秒 教学反思（自我评价）本微课通过用PPT的方式讲解了for和since的用法，因为是辨析两个单词的用法，因此我用了归纳法进行讲解，让学生在例子中发现规律，然后进行总结。但是，在讲解的过程中，我所举的例子可能太少了，给学生思考和练习的时间也很少，中等以下的学生可能对知识点还不是很理解。通过这节微课，我觉得在以后教学中，我要认真分析学生的认知能力，顾及大部分学生，然后寻找更好的教学方法，或者在讲解释可以使用多种方法，归纳法或者演绎法等，让学生理解所教授的内容。另一个不足之处是，我在制作课件的时候并没有很好地运用多媒体技术，因此，在以后的教学中，我还要多学习多媒体在教学中的运用。