later、after、ago、before的用法：

later、after、ago、before的用法：“一段时间+later/ago”分别表示“(多久)以后/以前”,主要用于过去时态。“after/before+某个时刻”分别表示“在某时刻之后/之前”,此时两个词是介词。ago与before：ago只能用于过去时,before用于完成时。如：He had an accident a week ago.(一周前出了一个事故).Some years later, the boy became a very famous singer.(数年后这个男孩成了著名的歌唱家).Have you been there before?(你从前到过那儿吗？).After a few years he gave up smoking.(过了几年他戒了烟。) 加入收藏夹主题：单词辨析 知识讲解 before和ago after和later 有什么区别内容：before和ago after和later 有什么区别 提交人：毛怡璇时间：7/31/2007 16:46:46主题：hi内容：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： I called him up last night， but his mother told me he had left for Wuhan two days before. She 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：I have never been to Beijing before.Have you ever seen a tiger before? I 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： I graduated from the college twenty years ago.I 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： He will come back before eleven oclock. Where did your brother study before he joined the army? It 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： He has been here since three years ago. I 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： I had never seen a Red Army man before I arrived in Xian. They 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 didnt 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 didnt 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 didnt 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 hadnt 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 hell 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。初中英语易混词辨析after，in，later after，in和later用来指时间时，都表示“在之后”，但它们的用法是有区别的。 当表示以现在时间为起点的“在之后”时，in后接时间段，after后接时间点。 He often comes back after ten oclock. 他经常十点后回来。 Hell be here in a week. 他将在一周后到这里。 当表示以过去某个时间为起点时，after之后可接时间点或时间段。而in只表示未来的事情，一般不用于过去某个时间。 After a few minutes she started to cry. 几分钟后，她开始哭了。 He said that he would come back in a year. 他说他一年后会回来。 after还可作连词，引导时间状语从句。 After he drank some water，he began to clean the table. 他喝了些水后，便开始擦桌子了。 Lets play baseball after school is over. 放学后我们玩棒球吧。 later多用作副词，意为“稍后、之后”，通常用于时间段之后，此时应与过去时连用。当然，它也可单独使用，表示以说话时为起点，不确定的时间以后，此时多与将来时连用。 At first she was asleep. Half an hour late/After half an hour she woke up. 开始她睡着了，半小时后醒来了。 The radio says that the sun will come out later. 收音机里说太阳稍后会出来。 自我测试 根据句意，用after，in或later填空。 1.Just seven the rain began to fall.