[正] We got to the top of the mountain at day break.
[析] at用于具体时刻之前，如：sunrise， midday， noon， sunset， midnight， night.
[误] Don’t sleep at daytime
[正] Don’t sleep in daytime.
[析] in 要用于较长的一段时间之内，如：in the morning / afternoon， 或 in the week / month / year. 或 in spring / supper /autumn / winter等等。
[误] We visited the old man in Sunday afternoon.
[正] We visited the old man on Sunday afternoon.
[析] in the morning， in the afternoon 如果在这两个短语中加入任何修饰词其前面的介词都要改为on， 如：on a cold morning， on the morning of July 14th
[误] He became a writter at his twenties
[正] He became a writter in his twenties
[析]这句话应译为：他在20多岁时就成了作家。在某人的一段生活时间段中要用介词in来表示，而在具体岁数时用at来表示。
[误] He went to New York to find a job in sixteen years old.
[正] He went to New York to find a job at sixteen.
[析] 在具体年岁前用at， 如：at the age of 12， at your age，等等。
[误] We went to swim in the river in a very hot day.
[正] We went to swim in the river on a very hot day.
[析] 具体某一天要用介词on， 又如：on New Year‘s Day
[误] I’m looking forward to seeing you on Christmas.
[正] I’m looking for ward to seeing you at Christmas.
[析]在节日的当天用on，而全部节日期间用at，Christmas是圣诞节期间，一般要有两周或更长的时间。
[误] I haven’t see you during the summer holidays.
[正] I haven’t seen you since the beginning of the summer holidays.
[析] during表示在某一段时间之内，所以一般不与完成时搭配，如：I visited a lot of museums during the holiday. 而for表示一段时间，可以用于完成时，如：I haven‘t see you for a long time. 而through 用来表示时间时则为“整整，全部的时间”。如：It rained through the night.而since则是表达主句动作的起始时间，一般要与完成时连用。
[误] At entering the classroom， I heard the good news.
[正] On entering the classroom， I heard the good news.
[析] On 加动名词表示“一……就”。本句的译文应是：我一进入教室就听见这个好消息了。又如：on hearing… 一听见， on arrival 一到达就……(on表示动作的名词)
[误] In the beginning of the book， there are some interesting stories.
[正] At the beginning of the book， there are some interesting stories.
[析] at the begining与at the end都是指某事物的开始与结束部分，均不指时间范围，而in the beginning 则是指开始一段时间。in the end=at last是指“最终，终于”之意。
[误] Till the end of next week. I will have finished this work.
[正] By the end of next week. I will have finished this work.
[析] by 引起的时间状语表示了动作的截止点，其意思为“不迟于某一时刻将工作做完”，所以主句一般是完成时态。当然可以有将来时态，如：I‘ll be there by five o’clock.而till则表达其一动作一直持续到某一时刻，但句中的动词一定要用持续性动词，而瞬间的截止性动词应用其否定句式，如：I won‘t finish this work till(until) next weekend.
[误] He came to London before last weekend.
[正] He had come to London before last weekend.
[正] He came to London two weeks ago.
[析] before 一般要与完成时连用，而ago则与一般过去时连用。
[误] I have studied English for three years gince I had come here.
[正] I have studied English for three years since I came here.
[析] since用来表达主句动作的开始时间，所以其引出的从句中应为过去时，而不能用完成时态
[误] I can help you repair this bike. You will get it after two hours.
[正] I can help you repair this bike. You will get it in two hours.
[析]中文经常讲两小时之后来取，两天内会修好，而这个介词在英文中要用in而不要用after.其原因有二，①after 多用于过去时，如：I arrived in New York. After three days， I found a job in the bank. ② after 加时间是表达一个不确定的时间范围，如：after three days， 即三天之后的哪一天都可以。所以在许诺若干时间内会完成某事时，一定要用介词in.
[误] Three days after he died.
[正] After three days he died.
[正] Three days later he died.
[析] after 与 later都可以用来表达一段时间之后，但它们所处的位置不同，after 在时间词前，而later在时间词后。
[误] She hid herself after the tree.
[正] She hid herself behind the tree.
[析] after多用来表达某动作之后，所以有的语法书中称它为动态介词，如：I run after him. After finishing my homework， I went to see a film. 而behind则多用于静态事物之后。
[误] There is a beautiful bird on the tree.
[正] There is a beautiful bird in the tree.
[析] 树上长出的果实，树叶要用on， 而其他外来的人、物体均要用in the tree.
[误] Shanghai is on the east of China.
[正] Shanghai is in the east of China.
[析] 在表达地理位置时有3个介词：in， on， to. in表示在某范围之内; on表示与某地区接壤;to则表示不相接。如：Japan is to the east of China.
[误] I arrived at New York on July 2nd.
[正] I arrived in New York on July 2nd.
[析] at用来表达较小的地方，而in用来表达较大的地方。at常用于at the school gate， at home， at a bus stop， at the station， at the cinema， at a small village.
[误] He lived in No. 3 Beijing Road.
[正] He lived at No. 3 Beijing Road.
[析] 在门牌号码前要用at， 并要注意它的惯用法：at the end of the street， at the foot of the mountain， at the top of the page.
[误] There is a colour TV set at the corner of the hall.
[正] There is a colour TV set in the corner of the hall.
[析] 在屋内的角落应用in，而墙的外角用at，如：There is a tree at the corner of the street.
[误] This weekend I’ll stay in Uncle Wang’s.
[正] This weekend I’ll stay at Uncle Wang’s.
[析] 要注意英文的特殊表达法，如：at a tailor’s shop (裁缝店)=at a tailor’s， at the doctor’s (去看病) at the bookseller’s (在书店) at uncle Wang’s (在王叔叔家)
[误] Do you know there is some good news on today’s newspaper?
[正] Do you know there is some good news in today’s newspaper?
[析] 在报纸上的新闻要用in， 而在具体某一版上，或某一页上则要用on.
[误] The school will begin on September 1st.
[正] School will begin on September 1st.
[析]这里的school应看作不可数名词泛指学校的课程，即开学之意。要注意，有些活动场所当表达正在从事该种活动时不要加冠词，如：at table (吃饭)， When I came to Tom’s home， they were at table. 还有： at desk (学习)，at work (工作) at school (上学)， in hospital (住医院) at church 作礼拜如加上定冠词则另有他意，如：at the school 即在学校工作或办事，in the hospital 即在医院工作或去看望病人。
[误] In my way to the station， I bought a newspaper to kill time.
[正] On my way to the station， I bought a newspaper to kill time.
[析]译文为：在去车站的路上我买了份报纸，为的是消磨时光“在……的路上”应用on one‘s way…。而 in the way 有挡道之意，如：Please move the chair it is in the way.
本文来自：逍遥右脑记忆 http://www.jiyifa.net/chuzhong/1242744.html
相关阅读：研究：你的年龄如何影响你的食欲？