學(xué)習(xí)英語并不難啊。你還在為英語成績低拖后腿而煩惱嗎？不要著急，小編為大家提供了新概念英語第2冊語法:表時間的介詞at、on、in的用法。相信加入學(xué)習(xí)當(dāng)中的你，很快便不再受英語的困擾！還在等什么？和小編一起來學(xué)習(xí)吧！
一、at
1、表示時刻，即幾點(diǎn)幾分(with particular points on the clock)
I’ll see you at five o’clock. (我五點(diǎn)和你見面。)
2、表示一天中的某個時間段(with particular points in the day)
The helicopter took off at midday and headed for the island. (直升機(jī)中午起飛，飛往那個島嶼。)
3、表示一周中的某個時間段，即工作日(weekday)和周末(weekend)(with particular points in the week)
What are you doing at the weekend?
4、表示某種特殊場合，如名字中不含day的節(jié)假日(with special celebrations)
At the New Year, millions of people travel home to be with their families(到了新年，成百上千萬的人會回到家里和家人團(tuán)聚。)
例外情況：如果是說在生日那天，不用at，而用on，因?yàn)樯漳翘焓侵妇唧w日期，請往下參考o(jì)n的用法。
【注意】
如果是用what time來提問，what time前面一般不用at。如：What time are you leaving? (你幾點(diǎn)走?)
但是在口語中也可以這么問：At what time are you leaving?
二、on
1、用在日期前(with dates)
We moved into this house on 2 October 1997. (我們是1997年10月2日搬進(jìn)這棟房子的。)
2、用在星期的單數(shù)前(with a singular day of the week to refer to one occasion)
I’ve got to go to London on Friday. (我周五就到倫敦了。)
3、用在星期的復(fù)數(shù)前(with a plural day of the week to refer to repeated events)
The office is closed on Fridays. (辦公室周五是關(guān)門的。)
特殊情況：口語中有時會省略on，如：Do you work Saturdays? (你周六上班的嗎?)
4、用在特殊日子前(with special dates)
What do you normally do on your birthday? (你生日那天一般都做些什么?)
三、in
1、用在一天中的某個時間段前，一般為固定用法(with parts of the day)
I’ll come and see you in the morning for a cup of coffee. (我上午來看你，一起喝杯咖啡。)
2、用在月份前(with months)
We usually go camping in July or August. (我們常在7月或8月份去露營。)
3、用在年份前(with years)
The house was built in 1835. (這座房子是1835年造好的。)
4、用在季節(jié)前(with seasons)
The garden is wonderful in the spring when all the flowers come out. (春天里，當(dāng)所有的花兒都開放時，花園很漂亮。)
5、用在較長的時間段前(with long periods of time)
The population of Europe doubled in the nineteenth century. (十九世紀(jì)時期，歐洲人口翻了一倍。)
6、用在一段時間前面( to say how long it takes someone to do something)
He was such a clever musician. He could learn a song in about five minutes. (他是個很聰明的音樂家，他可以在約5分鐘內(nèi)學(xué)會一首歌。)
7、用在“in+一段時間+'s+time”結(jié)構(gòu)中，表示將來時間，如in a year’s time和in two months’ time(with -'s construction to say when something will happen)
I won’t say goodbye because we’ll be seeing each other again in three days’ time. (我不跟你告別了，因?yàn)槿旌笪覀兙蜁僖娒娴摹?
【注意】上面這句話中的in three days' time 也可以用in three days。注意對比下面這個句子：
He ran the marathon in six hours and 20 minutes. (他在馬拉松比賽中用時6個小時20分鐘。)
四、特殊情況
1、at or on?
當(dāng)籠統(tǒng)指代假期或周末時，用at;當(dāng)特指某個具體的假期或周末時，用on。如：
We never go away at the New Year because the traffic is awful. (新年我們從不出門，因?yàn)槁飞咸铝恕?
On New Year’s Day, the whole family gets together. (在元旦那天，整個家人會團(tuán)聚在一起。)
I’ll go and see my mother at the weekend if the weather’s okay. (周末如果天氣好，我會去看望我母親。)
The folk festival is always held on the last weekend in July. (這個民間節(jié)日總是在7月的后一個周末舉行。)
注意：美語里用的更多的是：on the weekend。
2、in or on?
當(dāng)要表示籠統(tǒng)表示一天中的時間段morning、afternoon、evening和night時，一般用in，而且后面要加定冠詞the;當(dāng)表示具體某個時間段時，要用on。如：
I always work best in the morning. I often get tired in the afternoon. (我上午的工作效率總是好的，下午經(jīng)常覺得疲倦。)
The ship left the harbour on the morning of the ninth of November. (輪船在11月9日的早上離開了港口。)
In the evening they used to sit outside and watch the sun going down. (他們過去經(jīng)常在傍晚坐在外面看日落。)
It happened on a beautiful summer’s evening. (這件事情發(fā)生在一個美麗的夏日傍晚時分。)
【注意】
對于night，如果是籠統(tǒng)地講，就用at night，中間不插入任何成分;如果是特指某個夜晚，一般用in the night。如：
I was awake in the night, thinking about all the things that have happened. (夜里我醒了過來，一直想著發(fā)生的事情。)
‘It’s not safe to travel at night,’ the officer said. (警官說道：“夜里出行不安全?！?
3、at the end or in the end?
at the end后面一般要接of，表示“在...末”;in the end一般作為固定短語，后面不再接成分，表示“后”。如：
At the end of the film, everyone was crying. (電影快結(jié)束時，每個人都在哭。)
I looked everywhere for the book but couldn’t find it, so in the end I bought a new copy. (我到處找書，但還是找不到，所以后就買了本新的了。)
4、at the beginning or in the beginning?
與end的用法相似，at the beginning后面一般要接of，表示“在...開始”;in the beginning一般作為固定短語，后面不再接成分，表示“剛開始”。如：
At the beginning of every lesson, the teacher told the children a little story. (每節(jié)課一開始，老師都會給孩子們講個小故事。)
In the beginning, nobody understood what was happening, but after she explained everything very carefully, things were much clearer. (一開始，大家都不知道發(fā)生了什么事情，但是經(jīng)過她仔細(xì)解釋之后，一切都明白了。)
5、不用at、on、in的情況
如果時間前面有each、every,next、last、some、this、that、one、any和all等詞時，就不用表時間的介詞了。如：
He plays football every Saturday. (他每周六都踢足球。)
Are you free at two o’clock next Monday? (你下周二兩點(diǎn)有空嗎?