都用完成時(shí),完成時(shí)包括許多
since
adv.(常用于現(xiàn)在完成時(shí)或過去完成時(shí))
1.此后;從那時(shí)到現(xiàn)在
She left school three years ago and has worked as a nurse ever since.
她三年前畢業(yè),從那時(shí)起便一直當(dāng)護(hù)士.
2.之前,以前
prep.
1.(常用于現(xiàn)在完成時(shí)或過去完成時(shí))自...以來,從...至今
I haven't heard from him since last year.
我自去年以來未曾收到過他的信.
conj.
1.(常用于現(xiàn)在完成時(shí)或過去完成時(shí))自...以來,從...至今
It's been ten years since they married.
他們結(jié)婚到現(xiàn)在已經(jīng)十年了.
She has been living a hard life since her husband died.
她自從丈夫死后,一直過著艱苦的生活.
2.既然;因?yàn)?由于
He must have taken the book since it isn't here.
他一定是把書拿走了,因?yàn)闀巡辉谶@里了.
Since it is so hot,let's go swimming.
既然天氣這么熱,我們?nèi)ビ斡景?
since的用法主要有兩點(diǎn)：一是表示“自從……以來”,二是表示“既然”之意.但如果只了解詞的含義,而不了解其用法,在使用時(shí)就會造成錯誤.例如：I have not heard from him since I lived in Shanghai.
不少人會望文生義,將該句譯為：“自從我住在上海以來,就再也沒有收到他的信了.”而實(shí)際上這個(gè)句子的譯文并非如此,那么正確的含義是什么呢?
下面談?wù)剆ince作連詞引導(dǎo)時(shí)間狀語從句的用法.
一、若since引導(dǎo)的狀語從句的謂語動詞是終止性的過去時(shí),則從句表示的時(shí)間是“從動作開始的那一時(shí)刻起”.如：
He has studied very hard since he came to our school.自從他來到我們學(xué)校,他學(xué)習(xí)就非常努力.
We have been missing them since they left here自從他們離開這里,我們就一直很想念他們.
這是最常見的一種用法,此處不再多述.
二、若since引導(dǎo)的狀語從句的謂語動詞是持續(xù)性動詞或表示狀態(tài)的動詞的過去時(shí)時(shí),則從句表示的時(shí)間是“從那持續(xù)動作或狀態(tài)結(jié)束時(shí)算起”.如：
I haven’t heard any noise since I slept.Sleep 為持續(xù)性動詞,sleep的動作結(jié)束時(shí),即“醒來”時(shí),這句應(yīng)譯為“我醒后還未聽到任何聲音”.
John is now with his parents in New York,it is already three years since he was a teacher約翰現(xiàn)在和父母一起住在紐約,他不當(dāng)教師已經(jīng)三年了.
本文開始出現(xiàn)的那個(gè)句子就可以譯為“自從我離開上海,就再也沒有收到他的信.”這種譯法常被人們誤用,我們不妨再多舉幾個(gè)例子看看：
How long is it since you lived in Shanghai?你離開（沒住在）上海多久了?
It is half a month since he was a League member.他退團(tuán)（不當(dāng)團(tuán)員）半個(gè)月了.
It’s been quite some time since I was last in London我離開倫敦已很長時(shí)間了.
比較：He has written to me frequently since I was ill.自從我病愈以來,他屢次給我寫信.（從句謂語為狀態(tài)動詞）
He has written to me frequently since I fell ill.自從我生病以來,他就屢次給我寫信.（從句謂語為終止性動詞）
三、若since引導(dǎo)的狀語從句的謂語為持續(xù)性動詞的現(xiàn)在完成時(shí),則表示動作和狀態(tài)延續(xù)到現(xiàn)在（說話時(shí)刻）,其表示的時(shí)間的起點(diǎn)應(yīng)從動作發(fā)生之時(shí)算起.如：
I haven’t heard from him since he has lived there.
這里has lived表示動作的持續(xù)性,時(shí)間的起點(diǎn)應(yīng)從：“開始居住”時(shí)算起.因此此句可理解為“自從他（開始）住在那兒起,我就一直沒收到他的來信”.
Since we have owned a car,we have gone camping every year.自從我們自己有了汽車,我們每年都去野營.
試比較：1.Since I’ve been at this school,we have had three headmasters.自從我到這所學(xué)校,我們已換了三個(gè)校長了.
Since I was at this school,they have had three headmasters.自從我離開這所學(xué)校,他們已換了三個(gè)校長了.
2.He has never been to see me since I have been ill.自從我生病以來,他從未來看過我.
He has never been to see me since I was ill.自從我病愈以來,他從未來看過我.
由此可見,since引導(dǎo)的從句持續(xù)動詞的一般過去時(shí)和現(xiàn)在完成時(shí)所表示的意思恰好相反.換言之,前者以肯定的語法形式反映著否定的邏輯內(nèi)容,而后者的形式與內(nèi)容是一致的.
至于It's+一段時(shí)間+since…的句型與It has been +一段時(shí)間+since…意思相同.前者是口語說法,后者是規(guī)范說法.