介詞at、on、in用法

1、at，on和in是表示時(shí)間的常用介詞，用好這三個(gè)時(shí)間介詞，可以先抓住一個(gè)大的原則，即at某時(shí)刻, on某天, in某段時(shí)間，時(shí)間的跨度是由小到大。選用介詞at的場(chǎng)合：用于鐘點(diǎn)前at ten oclockat a quarter to six用于時(shí)刻前at noon/night/midnight(半夜)at sunrise(日出時(shí))at dusk(黃昏)at dawn/daybreak (黎明)eg:We will leave at daybreak.我們將在黎明時(shí)動(dòng)身。用于表示進(jìn)餐時(shí)間。如：at breakfast/lunch/supper(在早餐時(shí)/午餐時(shí)/晚餐時(shí))eg:He drinks

2、tea at breakfast.他在早餐時(shí)飲茶。用于表示年齡時(shí)。如：at 14 (=at the age of 14在14歲)eg:He left home at the age of 16.他十六歲離開(kāi)了家。用于一些固定短語(yǔ)或習(xí)慣搭配中。如：at Christmasat New Yearat Thanksgiving(感恩節(jié))at the beginning/end of last monthat the moment/ at that timeat this time of dayat a bad time of yearat first(起初)at last(終于)選用介詞on的場(chǎng)合：

3、用于星期、日期(包括該天的各部分)前on Sundays/weekdayson Monday morning / afternoon / eveningeg:Im flying home on Sunday afternoon.我星期四下午乘飛機(jī)回家?！霸谥苣奔瓤梢哉f(shuō)at weekends，也可以說(shuō)on weekendseg:I often go fishing on/ at weekends.我經(jīng)常在周末去釣魚(yú)。用于morning/afternoon/evening/night/day前，此時(shí)這類(lèi)名詞前多有修飾語(yǔ)或帶有of等引起的后置修飾語(yǔ)，指具體的或不具體的某一日on a cold af

4、ternoonon the night of October 1, 1997on the first dayon his birthdayon Friday afternoon用于公共節(jié)假日前：on Teachers Dayon Christmas DayEveon National Day特別注意：at，on都可用來(lái)表示“節(jié)假日”，但at側(cè)重指“休假的時(shí)節(jié)”，而不是指具體的哪一天；on側(cè)重指具體的時(shí)日，與它連用的短語(yǔ)中多含“Day”at New Year(在新年期間) at Christmas (在圣誕節(jié)期間)on New Years Day(在元旦那天) on Christmas Day

5、(在圣誕節(jié))選用介詞in的場(chǎng)合：用于泛指一天的上午、下午、傍晚如：in the morning/afternoon/evening/night用于某個(gè)較長(zhǎng)的時(shí)間，像世紀(jì)、朝代、年、月、季節(jié)in Marchin springin 1997in the twenty-first century(在二十一世紀(jì))in ones fifties(在某人50多歲時(shí))用于表示“從現(xiàn)在起，多久以后或多長(zhǎng)時(shí)間內(nèi)”的短語(yǔ)之前Shell see me again in a weeks time.一周后她再來(lái)看我。I can draw a beautiful horse in five minutes.我可以在五分鐘

6、內(nèi)畫(huà)好一匹好看的馬。There are seven days in a week.一周有七天。省略介詞的情況：有些情況，既不用in，也不用on和at，時(shí)間前面可不帶介詞。家長(zhǎng)可以讓孩子認(rèn)清標(biāo)志，注意哪些情況下要省略介詞，避免畫(huà)蛇添足。next，last，this，that與時(shí)間名詞連用作狀語(yǔ)時(shí)Were going to work on a farm next Sunday.下個(gè)星期天，我們要去農(nóng)場(chǎng)勞動(dòng)。They visited the Great Wall last year.去年他們參觀了長(zhǎng)城。today, tomorrow, yesterday, the day before yester