before／ago,since用法
since的用法总结
since的用法总结以下是小编为大家整理的since的用法总结,希望可以帮助到你们提高英语水平!since释义prep.从…以来; 自从…之后; 自从;adv.以后，此后; 后来; (距今几年)以前; (从那时候起几年)以前conj.自从…以来; 自从…的时候起; 既然; 因为since的用法一.Since作为介词后接某一确定的时间点，主句谓语动词是持续性动词，常与现在完成时态、现在完成进行时态或过去完成时态连用。
例如：1.He left the village in 1982 and I haven’t seen him since then.1982年他离开这个村子，从那以后我再没见过他。
2.She’s been working in a bank since leaving school.她中学毕业后就一直在一家银行工作。
3.He had spoken to her only once since the party. 自从那次聚会以来，他只跟她说过一次话。
二.Since作为副词表示从过去以来、以后或到现在的情形或状态，常与现在完成时态连用。
例如：1.He left home two weeks ago and we haven’t heard from him since. 他两周前离开了家，到现在我们一直没有他的消息。
2.He came to Zhenjiang 6 years ago and has lived here (ever) since.他6年前来到镇江，从此便住在这里。
三.since引导原因状语从句作为连词，since可引导原因状语从句，表示因为;既然;鉴于：例如：1.He didn’t come since he was busy.他因为忙，所以没有来。
2.Since this method doesn’t work,let’s try anoter.既然这种方法不行，我们就试用另一种吧。
before的用法归纳
before的用法是很多的人都比较想要了解的，在众人的心中before的用法是比较难的，我们都非常想要去了解before的用法，但是又谈何容易呢为了让大家更加快速的了解before的用法，下面我们就和教师一起去看看吧，希望对大家有所帮助。
prep.在……之前;先于，优于;当着……的面;与其……conj.在……之前;在……以前;比……早些;与其……adv.先前，从前;在前，在前方before一词含义广泛，是高考考查的热点词汇之一，但部分考生对该词的用法模糊不清。
为了帮助大家掌握，现就对before的用法归纳如下：一、 before用作连词1. before用作连词时，意思是“在……之前;还没来得及…… 就”。
强调主句或从句谓语动词表示的动作发生得过早或过快?例如：Before she could move, she heard a great noise, which grew to a terrible roar. 她还没来得及动弹，就听见有很响的声音，接着就成了可怕的隆隆轰鸣声。
Before I could say a word, she had stormed out of the room. 不等我说一句话，她就冲出了房间。
Don’t count your chickens before they are hatched. 不要高兴得过早。
I must finish my homework before I watch TV.我必须做完作业才能看电视。
It still took seven years before they finally got married.?过了七年他们才最终得以成婚。
It will be only a few minutes before she comes back.?她过几分钟就会回来。
He announced the ending of the meeting before I could get in a word.?没容得我插上一句话,他就宣布散会了??Someone called me up in the middle of the night, but they hung up before I could answer the phone.有人半夜给我打电话,但我还未来得及接他就把电话挂断了??They had talked only a few minutes before they found they were quite different in opinion.他们才谈了几分钟就发现他们的意见很不一致??注意：before从句若是一个将来的动作，则用一般现在时代替一般将来时，如上句中的comes。
before的用法归纳
before的用法是很多的人都比较想要了解的，在众人的心中before的用法是比较难的，我们都非常想要去了解before的用法，但是又谈何容易呢?为了让大家更加快速的了解before的用法，下面我们就和教师一起去看看吧，希望对大家有所帮助。
prep.在……之前;先于，优于;当着……的面;与其……conj.在……之前;在……以前;比……早些;与其……adv.先前，从前;在前，在前方before一词含义广泛，是高考考查的热点词汇之一，但部分考生对该词的用法模糊不清。
为了帮助大家掌握，现就对before的用法归纳如下：一、before用作连词1. before用作连词时，意思是“在……之前;还没来得及…… 就”。
强调主句或从句谓语动词表示的动作发生得过早或过快｡例如：Before she could move, she heard a great noise, which grew to a terrible roar. 她还没来得及动弹，就听见有很响的声音，接着就成了可怕的隆隆轰鸣声。
Before I could say a word, she had stormed out of the room. 不等我说一句话，她就冲出了房间。
Don’t count your chickens before they are hatched. 不要高兴得过早。
I must finish my homework before I watch TV.我必须做完作业才能看电视。
It still took seven years before they finally got married. 过了七年他们才最终得以成婚。
It will be only a few minutes before she comes back. 她过几分钟就会回来。
He announced the ending of the meeting before I could get in a word. 没容得我插上一句话,他就宣布散会了｡Someone called me up in the middle of the night, but they hung up before I could answer the phone.有人半夜给我打电话,但我还未来得及接他就把电话挂断了｡They had talked only a few minutes before they found they were quite different in opinion.他们才谈了几分钟就发现他们的意见很不一致｡注意：before从句若是一个将来的动作，则用一般现在时代替一般将来时，如上句中的comes。
after,before,since用法区别
after，before，since用法区别1.after的用法小结1. 用作介词，与一段时间连用表示“在…之后”时，注意它与in的区别：after表示以过去时间为起点的一段时间以后，且通常与过去时态连用；而in则表示以现在为起点的一段时间以后：He came backafter two days. 他两天后就回来了。
He will come back in twodays. 他过两天就回来。
但after 若是与一点时间连用，则可与过去时态也可与将来时态连用：H e came back after 4 o’clock. 他是四点钟以后回来的。
He will come back after next month. 他将在下个月以后回来。
2. 用作连词引导时间状语从句时注意：若主句用将来时态(或含有将来意味)，则时间状语从句要用一般现在时态(表将来意义)，而不能直接使用将来时态：他回来后我就走。
正：I’ll leave after he comes back.误：I’ll leave after he will come back.3. 用作副词，表示“后来”、“ (一段时间)以后”，通常放在表示时间的副词之后：soon after 不久以后two days after 两天后4. 用于习语after all 终究，毕竟：I was right after all. 毕竟我是对的。
After all, he’s only six years old. 毕竟，他才六岁。
2.Before的用法小结高三课本第十五单元，INTER GATING SKILLS 和WORKBOOK READING部分有如下的句子：⒈The shop was successful，but it was about sixty years before people started to buy jeans for fashion as well as for work.⒉However，it probably will not be long before the other mountainous areas of China such as Sichuan，Xinjiang and Yunnan are developed，and as more facilities become available，prices will almost certainly fall.其中涉及到before的用法，下面就其用法进行总结。
after,before,since用法区别
after，before，since用法区别的用法小结1. 用作介词，与一段时间连用表示“在…之后”时，注意它与in的区别：after表示以过去时间为起点的一段时间以后，且通常与过去时态连用；而in则表示以现在为起点的一段时间以后：He came backafter two days. 他两天后就回来了。
He will come back in twodays. 他过两天就回来。
但after 若是与一点时间连用，则可与过去时态也可与将来时态连用：He came back after 4 o’clock. 他是四点钟以后回来的。
He will come back after next month. 他将在下个月以后回来。
2. 用作连词引导时间状语从句时注意：若主句用将来时态(或含有将来意味)，则时间状语从句要用一般现在时态(表将来意义)，而不能直接使用将来时态：他回来后我就走。
正：I’ll leave after he comes back.误：I’ll leave after he will come back.3. 用作副词，表示“后来”、“ (一段时间)以后”，通常放在表示时间的副词之后：soon after 不久以后two days after 两天后4. 用于习语after all 终究，毕竟：I was right after all. 毕竟我是对的。
After all, he’s only six years old. 毕竟，他才六岁。
的用法小结高三课本第十五单元，INTER GATING SKILLS 和WORKBOOK READING部分有如下的句子：⒈The shop was successful，but it was about sixty years before people started to buy jeans for fashion as well as for work.⒉However，it probably will not be long before the other mountainous areas of China such as Sichuan，Xinjiang and Yunnan are developed，and as more facilities become available，prices will almost certainly fall.其中涉及到before的用法，下面就其用法进行总结。
before的用法归纳
精心整理before的用法是很多的人都比较想要了解的，在众人的心中before的用法是比较难的，我们都非常想要去了解before 的用法，但是又谈何容易呢?为了让大家更加快速的了解before的用法，下面我们就和教师一起去看看吧，希望对大家有所帮助。
现就对及eroar.她还没来得及动弹，就听见有很响的声音，接着就成了可怕的隆隆轰鸣声。
BeforeIcouldsayaword,shehadstormedoutoftheroom.不等我说一句话，她就冲出了房间。
Don’tcountyourchickensbeforetheyarehatched.不要高兴得过早。
ImustfinishmyhomeworkbeforeIwatchTV.我必须做完作业才能看电视。
Itstilltooksevenyearsbeforetheyfinallygotmarried.?过了七年他们才最终得以成婚。
一致注意：before从句若是一个将来的动作，则用一般现在时代替一般将来时，如上句中的comes。
2.用于It+be+时间段+before...句型中，意思是“在……之后才……”。
例如：ItwillbefiveyearsbeforeIcomeback.我五年后才能回来。
Itwasnotlongbeforetheenemywasdrivenoutoftheircountry.不久之后，敌人就被赶走了。
如果主句中用否定式，则表示“不多久……就”。
Itwon’tbelongb eforetheyunderstandeachother.他们不久就他之前”（1成（2Ladiesbeforegentlemen.女士优先。
（3）表示位置，与behind相对（相当于infrontof）。
如：BeforeLucyisLily.?莉莉在露茜的前面。
Don’tputthecartbeforet hehorse.不要本末倒置。
（4）表示“在……面前；与……面对面”。
since用法
时间概念的Since用法归纳时间概念的Since 用法归纳江苏省泰州第二中学韩宏华一、副词用法：可翻译“后来、以来、以前、以后、其后、从那时以后/ 从此”等，还可与其它词构成词组表示类似的时间意思。
1．与完成时态连用等于before, eg ：I haven’t seen him since. （我从此没有见过他。
）He said that his father had died five years since. ( 他说他父亲5 年前就死了。
) 2．与过去时态连用等于ago, eg ：It happened many years since. ( 此事是数年前发生的。
) His father died five years since. (5 年前他父亲就死了。
) 3．构成的词组均用于完成时态, eg: a) He went to Nanjing in 1980 and has lived there ever since (=ever before 此后一直). b) We have seen that film long since (=long before 很久以前). c) Our great country has never since (=never before 空前) been so prosperous, as it is today. 二、连词用法：可翻译“自从… 的时候起、从此、从… 以来、… 以后”等，引导时间状语从句，区分如下：1．主句用现在完成时态，since 从句用短暂动词的过去一般时态表示从句的动作结束：We have both changed since we parted. ( 自从我们分手以来，我们都有了变化.) 2．主句用现在完成时态，since 从句用be 动词过去一般时态表示从句的状态结束: He has never been to see me since I was ill. ( 自从我病好以来, 他从未来看望我.) 3．主句用现在完成时态，since 从句用be 动词的现在完成时态表示从句的状态延续: He has never been to see me since I have been ill. ( 自从我生病以来, 他从未来看望我.) 4．主句用现在完成时态，since 从句用延续动词的现在完成时态表示从句的动作延续: 5．He hasn’t seen me since I have lived here. ( 自从我住在这里以来, 他还没有看望过我.) 6．主句用现在完成时态，since 从句用延续动词的一般时态表示从句的动作结束: He hasn’t seen me since I lived here. ( 自从我不住在这里以来, 他就没有看望过我.) =He hasn’t seen me since I left here. 三、句型用法：１．主句用现在完成时，从句用一般现在时：I have done translation since I know English. ２．主句用系动词的一般现在时，从句用一般过去时：He feels much better since he took some medicine. ３．主句用现在进行时，从句用一般过去时: I am walking to work since my bike broke down. ４．It is + 时段＋since 从句（短暂动词的过去式）It is two years since he joined the army. ５．It was + 时段＋since 从句（短暂动词的过去完成式）It was four years since we had parted. ６．It has been+ 时段＋since 从句（短暂动词的现在完成时）It has been about five months since I have heard from him. ７．It is + 时段＋since 从句（延续动词的现在完成时）It is a long while since I have been at home. ( 我自从离家已有好长一段时间了。
Before和ago的区别
before agobefore和ago都能表示在一段时间以前，但是二者的内涵和具体用法有明显的区别：1. before表示从过去或将来某一时间算起多少时间以前，由于与这一时间状语连用的行为先发生在过去或将来某一时刻之前，因此往往出现在过去完成时态或将来完成时态中。
例如：① I called him up last night， but his mother told me he had left for Wuhantwo days before.② She said that she had marrie d him five yearsbefore.2.如果不具体表明多少时间以前，before意为"从前；以前"，表示从现在开始追溯到过去一段时间，或者主句的谓语动词表示的是经常、反复发生的行为，以副词的形式置于句末，可以用在现在完成时态中。
例如：①I have neverbeen to Beijin g before.②Have you ever seen a tigerbefore?③ I oftengo over the lesson s that I have learne d a few days before.注意： before前的时间状语如果是特定的，含义不一样。
试比较：He said he had arrive d here a day before. (一天前)He said he had arrive d here the day before. (前一天)3. ago指的是从现在起到过去时间的某一点的一段时间。
这个时间状语常与一般过去时态或过去进行时态连用。
例如：① I gradua ted from the colleg e twenty yearsago.②I was askedwhat I was doinga monthago.4. 表示在某一时间点或事件以前时，只能用bef ore，不用ago。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
before和ago都能表示在一段时间以前，但是二者的内涵和具体用法有明显的区别：1. before表示从过去或将来某一时间算起多少时间以前，由于与这一时间状语连用的行为先发生在过去或将来某一时刻之前，因此往往出现在过去完成时态或将来完成时态中。
例如：①I called him up last night，but his mother told me he had left for Wuhan two days before.②She said that she had married him five years before.2.如果不具体表明多少时间以前，before意为"从前；以前"，表示从现在开始追溯到过去一段时间，或者主句的谓语动词表示的是经常、反复发生的行为，以副词的形式置于句末，可以用在现在完成时态中。
例如：①I have never been to Beijing before.②Have you ever seen a tiger before?③I often go over the lessons that I have learned a few days before.注意：before前的时间状语如果是特定的，含义不一样。
试比较：He said he had arrived here a day before. (一天前)He said he had arrived here the day before. (前一天)3. ago指的是从现在起到过去时间的某一点的一段时间。
这个时间状语常与一般过去时态或过去进行时态连用。
例如：①I graduated from the college twenty years ago.②I was asked what I was doing a month ago.4. 表示在某一时间点或事件以前时，只能用before，不用ago。
因为这种用法是将before当作介词或连词使用。
ago不具有这种功能。
例如：①He will come back before eleven o'clock.②Where did your brother study before he joined the army?③It was hoped that this would be achieved before the year 2006.5.按语法规则，ago只能与一般过去时连用，但在since three years ago这类短语中能与现在完成时态连用。
因为three years ago构成一个名词短语，共同作since的宾格，意为"自从三年前以来"。
例如：①He has been here since three years ago.②I have taught English in this school since twenty years ago.6. 含before的从句一般不用将来时态，如果采用"will / would +V."时，一般被认为是情态或虚拟语气。
例如：I would die before I would confess to it.7.如果before从句是一般过去时态，所暗示的是过去发生的事，主句则宜用过去完成时，语义偏重于过去某阶段的行为或状况时，还可与一般过去时态连用。
例如：①I had never seen a Red Army man before I arrived in Xi'an.②They asked me things that happened before the boy was born.8. 不少的语法书上说，before引导的从句习惯上不与否定的主句连用，要用until。
实际上二者都可以，有时在意义上有些区别。
试比较：He didn't arrive until I returned. 直到我回来时他才到达。
He did not arrive before I returned. 在我回来之前他尚未到达。
I didn't manage to do it until you had explained how. 直到你解释了如何干，我才设法完成了那项工作。
I didn't manage to do it before you had explained how. 你解释了如何干之后，我才设法完成了那件工作。
9. before在句中的含义比较灵活，虽然before引导的也是一个时间状语，但译成汉语时却不必死译为"在……以前"。
可以采取下面几种译法：(A)译为"……才"；(B)译为"……就"；(C)译为"尚未"、"还没有"、"来不及"、"不要"、"别"；(D)译为"在……的时候还没有"；(E)译为"如果"、"否则"、"免得"；(F)译为"到"、"等到"、"没等……就"；(G)译为"然后"等。
例如：A. It will be five years before we meet again. 要等五年我们才能再见面。
We waited a long time before the train arrived. 我们等了很长时间火车才到达。
B. I hadn't waited long before he came. 我没等多久他就来了。
He had not gone a mile before he felt tired. 还没走一英里路，他就觉得累了。
C. His father died before he was born. 他尚未出世他父亲就去世了。
Catch him before he escapes. 抓住他，别让他跑了。
Take this computer before you change your mind. 买了这台电脑，不要三心二意了。
D. We arrived there before it began to rain. 我们到达那里的时候还没下雨。
E. Go before I call the police. 走吧，否则我叫警察了。
I had better go now before it is too late. 我最好现在就走，免得太迟。
Pigs will fly before he'll be a scientist. 如果他当科学家，猪都会飞了。
F. The crops will die before the rain fall. 等到天下雨，庄稼早枯死了。
Before I could sit down, he offered me a cup of tea. 没等我坐下，他就给我端上一杯茶。
G. I shaved before I went to the party. 我刮了脸，然后去参加宴会。
since的用法：译作“自从…以来”(1)接时间点：如I have stayed in that country since 1995. 要求：谓v.用现在完成时，而且须是延续性动词。
(2)接一段时间+ ago：如They have lived in that house since two years ago. 要求：谓v.用现在完成时，而且须是延续性动词。
(3)接时间状语从句：如I have loved her since I met her last time. / Lily has stayed at home since she left school. 要求：主句的谓v.用现在完成时，而且须是延续性动词；从句的谓v.用一般过去时，而且须是终止性动词。
(4)用于句型“It’s / It has been + 一段时间+ since + 时间状语从句”中，译作“自从…以来, 已经…(时间)了”。
如It’s / has been three months since he moved to this city. 要求：主句的谓v.用一般现在时或现在完成时；从句的谓v.用一般过去时，而且须是终止性动词。
(5)用于句型“一段时间+ has passed since + 时间状语从句”中，译作“自从…以来, …(时间)已经过去了”。
如上个例句还可写成：Three months has passed since he moved to this city. 要求：主句的谓v.用现在完成时，而且动词必须是has passed；从句的谓v.用一般过去时，而且须是终止性动词。
(6)注：当since用于否定句时，主句的谓v.可以是终止性动词。
如He hasn’t seen the film since last month.(7)相关词组：“从那时起”：ever since、since then、from then on.注：ever since作为一个词组，放句尾可单独使用。
如I have given up smoking ever since. 另外，还可在since后接句子。
since前加ever，只是加重语气而已。
如I have given up smoking ever since I caught a bad cough.(8) since还可引导原因状语从句，译作“由于；因为”，相当于because。
如Since he was lazy, he didn’t finish his homework。