一些英语词语的用法.1.as soon as2.until3.while4.when5.since希望能详细回答..谢谢

一些英语词语的用法.
1.as soon as
2.until
3.while
4.when
5.since
希望能详细回答..谢谢了

1as soon as
(1)一．．．就．．
eg:I'll come here as soon as finish the work.
(2)如果..那么早(快)
eg:They didn't arrive as soon as we had expected.
2.until
一、 介词until
作介词的until 的英文解释是up to a specified time (直到某一时刻)或up to the time of a specified event (直到发生某事).但注意观察下列句子,我们还可留意到until 在具体运用中的细微之处.
1. 用于肯定句中：
1) It may last until Friday. 这可能要延续到星期五.
2) He will be working until 5 o'clock. 他将一直工作到五点钟.
3) She was a bank clerk until the war, when she trained as a nurse. 她战前是个银行职员,战时受训当了护士.
不难看出until 用于肯定句中,表示句子的动作一直持续到until短语所表示的时间为止,即表示动作的终点.一般可译为“直到……时(为止)”或“在……以前”.在这种用法中,句子的谓语动词必须是持续动词(非瞬间动词),如live, wait , last, love, like, stay, work, continue 等.
2. 用于否定句中：
1) The secret was never told until after the old man's death. 这个秘密在老人去世后才说出来.
2) Don't open it until your birthday. 等到你过生日那天再打开.
3) She didn't sleep until eight. 她八点钟才睡觉.
不难看出until用于否定句中,表示句子的动作直到until短语所表示的时间才开始发生,即表示动作的起点.一般译为“直到……才”或“直到……之前(……还不)” .
二、 连词until
以同样的方式分析作连词的until的用法.作连词用的until的英文释义是up to the time when(直到……时为止).
1. 用于肯定句中：
1) Heat can be conducted from a hot body to a cooler one until both are at the same temperature.热可以从一个热的物体传到一个较冷的物体,直到两者温度相同为止.
2) Continue in this direction until you see a sign. 一直朝着这个方向走就会看见指示牌了.
3) He ran until he was breathless. 他一直跑到气喘吁吁才停下.
不难看出,作连词的until用于肯定句中,表示主句的动作一直持续到从句动作发生或状态出现时为止.一般可译为“……直到……为止”.在这种用法中,主句的谓语动词必须是持续动词(非瞬间动词),如live, wait , last, love, like, stay, work, continue 等.
2. 用于否定句中：
1) I hadn't realized she was foreign until she spoke. 她不说话我还一直不知道她是个外国人.
2) I won't stop shouting until you let me go. 你不放我,我就一直喊叫.
3) Among the great mathematicians there are about as many who showed mathematical talents in childhood as there are those who showed none at all until they are older. 在伟大的数学家中,童年就显露数学才华的人和直到相当年龄才显露才华的人差不多一样多.
不难看出,作连词的until用于否定句中,表示主句的动作在从句的动作发生之前尚未发生,或者说主句的动作在从句的动作发生之后才开始.一般可译为“直到……才”.
3.while
一、 while 用作名词时,意为“一段时间,一会儿”.
二、 while 用作连词时,有以下几种含义：
1. 意为“当……时候,和……同时”,引导时间状语从句.
三、 while 引导状语从句时,应注意以下几点：
1. while 引导的时间状语从句既可放在句首,也可放在句末；而 while 引导的让步状语从句一般放在句首,不放在句末.另外,也可以从意义上加以区分.
4. while 引导的状语从句还可以表示“某个动作正在进行的同时,另一个动作也在进行之中”.
4.when
when,while,as引导时间状语从句的区别
when,while,as显然都可以引导时间状语从句,但用法区别非常大.
一、when可以和延续性动词连用,也可以和短暂性动词连用；而while和as只能和延续性动词连用.
① Why do you want a new job when youve got such a good one already?（get为短暂性动词）你已经找到如此好的工作,为何还想再找新的?
②Sorry,I was out when you called me．（call为短暂性动词）对不起,你打电话时我刚好外出了.
③Strike while the iron is hot．（is为延续性动词,表示一种持续的状态）趁热打铁.
④ The students took notes as they listened．（listen为延续性动词）学生们边听课边做笔记.
二、when从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while和as从句的谓语动作必须是和主句谓语动作同时发生.
1．从句动作在主句动作前发生,只用 when.
①When he had finished his homework,he took a short rest．（finished先发生）当他完成作业后,他休息了一会儿.
②When I got to the airport,the guests had left．（got to后发生）当我赶到飞机场时,客人们已经离开了.
2．从句动作和主句动作同时发生,且从句动作为延续性动词时,when,while,as都可使用.
①When ／While ／As we were dancing,a stranger came in．（dance为延续性动词）当我们跳舞时,一位陌生人走了进来.
②When ／While ／As she was making a phonecall,I was writing a letter．（make为延续性动词）当她在打电话时,我正在写信.
3．当主句、从句动作同时进行,从句动作的时间概念淡化,而主要表示主句动作发生的背景或条件时,只能用 as.这时,as常表示“随着……”；“一边……,一边……”之意.
① As the time went on,the weather got worse．（as表示“随着……”之意）
② The atmosphere gets thinner and thinner as the height increases．随着高度的增加,大气越来越稀薄.
③As years go by,China is getting stronger and richer．随着时间一年一年过去,中国变得越来越富强了.
④The little girls sang as they went．小姑娘们一边走,一边唱.
⑤The sad mother sat on the roadside,shouting as she was crying．伤心的妈妈坐在路边,边哭边叫.
4．在将来时从句中,常用when,且从句须用一般时代替将来时.
①You shall borrow the book when I have finished reading it．在我读完这本书后,你可以借阅.
②When the manager comes here for a visit next week,Ill talk with him about this．下周,经理来这参观时,我会和他谈谈此事.
三、when用于表示“一……就……”的句型中（指过去的事情）.
sb．had hardly（＝scarcely） done sth．when．．．＝Hardly ／ Scarcely had sb．done sth．when．．．
①I had hardly ／scarcely closed my eyes when someone knocked at the door．＝Hardly ／ Scarcely had I closed my eyes when someone knocked at the door．我刚一闭上眼,就有人在敲门了.
②I had hardly ／scarcely entered my room when the telephone rang．＝Hardly ／Scarcely had I entered my room when the telephone rang．我刚一走进房门,电话就响了.
5.since
since的用法主要有两点：一是表示“自从……以来”,二是表示“既然”之意.但如果只了解词的含义,而不了解其用法,在使用时就会造成错误.例如：I have not heard from him since I lived in Shanghai.
不少人会望文生义,将该句译为：“自从我住在上海以来,就再也没有收到他的信了.”而实际上这个句子的译文并非如此,那么正确的含义是什么呢?
下面谈谈since作连词引导时间状语从句的用法.
一、若since引导的状语从句的谓语动词是终止性的过去时,则从句表示的时间是“从动作开始的那一时刻起”.如：
He has studied very hard since he came to our school.自从他来到我们学校,他学习就非常努力.
We have been missing them since they left here自从他们离开这里,我们就一直很想念他们.
这是最常见的一种用法,此处不再多述.
二、若since引导的状语从句的谓语动词是持续性动词或表示状态的动词的过去时时,则从句表示的时间是“从那持续动作或状态结束时算起”.如：
I haven’t heard any noise since I slept. Sleep 为持续性动词,sleep的动作结束时,即“醒来”时,这句应译为“我醒后还未听到任何声音”.
John is now with his parents in New York, it is already three years since he was a teacher约翰现在和父母一起住在纽约,他不当教师已经三年了.
本文开始出现的那个句子就可以译为“自从我离开上海,就再也没有收到他的信.”这种译法常被人们误用,我们不妨再多举几个例子看看：
How long is it since you lived in Shanghai?你离开（没住在）上海多久了?
It is half a month since he was a League member.他退团（不当团员）半个月了.
It’s been quite some time since I was last in London我离开伦敦已很长时间了.
比较：He has written to me frequently since I was ill.自从我病愈以来,他屡次给我写信.（从句谓语为状态动词）
He has written to me frequently since I fell ill.自从我生病以来,他就屡次给我写信.（从句谓语为终止性动词）
三、若since引导的状语从句的谓语为持续性动词的现在完成时,则表示动作和状态延续到现在（说话时刻）,其表示的时间的起点应从动作发生之时算起.如：
I haven’t heard from him since he has lived there.
这里has lived表示动作的持续性,时间的起点应从：“开始居住”时算起.因此此句可理解为“自从他（开始）住在那儿起,我就一直没收到他的来信”.
Since we have owned a car, we have gone camping every year.自从我们自己有了汽车,我们每年都去野营.
试比较：1. Since I’ve been at this school, we have had three headmasters.自从我到这所学校,我们已换了三个校长了.
Since I was at this school, they have had three headmasters.自从我离开这所学校,他们已换了三个校长了.
2.He has never been to see me since I have been ill. 自从我生病以来,他从未来看过我.
He has never been to see me since I was ill. 自从我病愈以来,他从未来看过我.
由此可见,since引导的从句持续动词的一般过去时和现在完成时所表示的意思恰好相反.换言之,前者以肯定的语法形式反映着否定的逻辑内容,而后者的形式与内容是一致的.
至于It is +一段时间+since…的句型与It has been +一段时间+since…意思相同.前者是规范说法,后者是口语说法.
应注意的是,在这种结构中,since引导的从句绝对不能用否定式的谓语动词来表示否定意义,下面两句都错了：
It is a long time since he didn’t study English.
It’s two months since you didn’t come to see me.
正确的说法为：
It’s a long time since he studied English 他好久没学英语了.
You haven’t come to see me for two months. 你有两个月没来看我了