用in
介词in, on, at在表示时间时的用法区别
①in时间范围大（一天以上）如：in Tanuary, in winter, in
1999;泛指在上午，下午，晚上，如：in the morning(afternoon, evening).
习惯用法：in the daytime 在白天。
②on指在某一天或某一天的上午，下午，晚上，如：on Monday,
on Sunday afternoon, on July 1, 1999
③at时间最短，一般表示点时间，如at six o’clock, at three
thirty.习惯用法：at night, at noon, at this time of year.
in, on和at在表达时间方面的区别
in 表示在某年、某季节、某月、某周、某天和某段时间
in a year在一年中
in spring 在春季
in September 在九月
in a week 在一周中
in the morning/afternoon/evening 在上午/下午/傍晚
但在中午，在夜晚则用at noon/night
on 表示某一天或某一天的某段时间
on Monday 在周一
on Monday afternoon 在周一下午
on March 7th 在3月7日
on March 7th, 1998. 在1998年3月7日
on the morning of March 7th, 1998. 在1998年3月7日上午
at 表示某个具体时刻。
at eight o’clock 在8点钟
at this time of the year 在一年中的这个时候
at the moment 在那一时刻
at that time 在那时
注意：在英语中，如果时间名词前用this, last, next 等修饰时，像这样的表示，“在某时”的时间短语前，并不需要何
介词。
例如：last month, last week, this year, this week, next year, the next day, the next year等。
1．What’s the weather like in spring/summer/autumn/winter in your country?
你们国家春天/夏天/秋天/冬天的天气怎么样？
in 在年、月、周较长时间内in a week 在里面in the room 用某种语言in English 穿着 in red
on 某日、某日的上下午on Sunday afternoon 在……上面 on the desk 靠吃……为生live on rice 关于 a book on Physics
〔误〕 We got to the top of the mountain in daybreak.
〔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.
