1.at on in
a)at用來(lái)表示時(shí)間時(shí),通常指時(shí)間的某一點(diǎn)。例如:at five o’clock atnoon atmidnight
b)on用來(lái)表示某一段時(shí)間,特指某天或某天的上午 下午或晚上。例如:on Sunday,on October,on Saturday morning.
c)in也可用來(lái)表示一段時(shí)間,但多指長(zhǎng)于一天或不到一天的時(shí)間段。例如:inJanuary,insummer, in1988, in the morning ,in the evening.
2.in與during
a)during用來(lái)表示一段時(shí)間,其意義大致相當(dāng)于in的用法。一般來(lái)說(shuō),凡是能用in的地方,也可以用during.例如:He came to see me during my absence.Don’t go to see his wife in his absence.
B)during與in的區(qū)別在于during強(qiáng)調(diào)時(shí)間的延續(xù)性,而in則只是一般指某一時(shí)間。試比較:They visited many cities during their stay in China.Her grandpa was killed in the war.
3.in for during
a)“in+時(shí)間”與“for+時(shí)間”都可表示一段時(shí)間,但“for+時(shí)間”表示“有多久”,而“in+時(shí)間”則表示“在何時(shí)”。例如:We worked there for the winter.They worked there in winter.
以上兩例中,in winter強(qiáng)調(diào)“在冬季”,不一定包括整個(gè)冬季時(shí)間,而for the winter則強(qiáng)調(diào)“整個(gè)冬天”。
b)for用來(lái)表示一般時(shí)間,常跟具體的時(shí)間段。例如 for a few days for 3 weeks for five months等
4.since與after
都可以用來(lái)引導(dǎo)表示從過(guò)去某一點(diǎn)開(kāi)始的時(shí)間段詞組。它們的不同之處在于:
a)since引導(dǎo)的詞組所表示的時(shí)間一直延續(xù)到說(shuō)話時(shí)為止,因而要與現(xiàn)在完成時(shí)連用。例如:He has been there twice since 1982.I have done nothing since six o’clock.
b)after引導(dǎo)的詞組所表示的時(shí)間是純系過(guò)去,并不延續(xù)到說(shuō)話時(shí),因此要和一般過(guò)去時(shí)連用。例如:He went home after school.
5.till until與to
a)介詞till/until常用于“from.……till/until”結(jié)構(gòu)中,表示“一個(gè)動(dòng)作的終結(jié)”。介詞to常用在“from.……to”的結(jié)構(gòu)中,用來(lái)表示“一個(gè)階段的終結(jié)”。兩者在這種結(jié)構(gòu)中意義十分接近。例如:The Americans stayed here from June to September.He studies from morning till/until night everyday.
b)to可用在表示鐘點(diǎn)的詞前。我們說(shuō)It’s six tofive 但不能說(shuō)It’s six till/until five.反之在某些能用till/until的場(chǎng)合,卻不能用to.例如:在“not.……until”結(jié)構(gòu)中,我們說(shuō)I didn’t go to bed till/until ten o’clock.卻不能說(shuō)I didn’t go to bed to ten o’clock.
c)till與until也有細(xì)微區(qū)別。till常用在非正式文體或口語(yǔ)中,而until則常用于正式文體及比較正式的場(chǎng)合。另外,在句首多用until.
6.by before
a)by表示時(shí)間時(shí),意思是“到……以前”、“不遲于”、“到……時(shí)(為止)”。例如:by supper time by the end of last term
b)before表示時(shí)間,意為“在……以前”。例如:before liberation the day before yesterday
c)by與before的區(qū)別在于,by短語(yǔ)表示時(shí)間,強(qiáng)調(diào)“終止點(diǎn)”,而before短語(yǔ)表示時(shí)間,強(qiáng)調(diào)“起始點(diǎn)”。例如:Your son will be all right by suppertime.
句中的by suppertime表示從說(shuō)話時(shí)到晚飯前這段時(shí)間。而before構(gòu)成短語(yǔ)則表示從某一時(shí)間或事件之前,例如:The poor children couldn’t go to school before liberation.