语法要精，就用奥风！ 第六讲：介词 一. 介词的语法意义 介词是表示名词（或名词性结构的词）和句中其他词之间关系的一类词，一般置于名词之前 。 分类： 表示地点、表示时间、表示原因/ 目的、表示所属或伴随、表示方法/手段 二.介词详解 1 . 表示时间的介词 (1) at 用于表示钟点、一天中的某个时间点（如正午、拂晓、日落、那时）、某段时间、(节假日)期间或某些词组中。 如：at six o’clock; at noon; at daybreak; at night；at the weekend；at Christmas; at Easter；at war；at risk；at the beginning of at the meeting; at the end of; at the age of (2). on 用于表示星期、日期或具体的上午/下午/晚上等。 如： on May 1；on Monday； on Christmas Eve；on a cold night；on July 7, 2010 ； on weekends；on Sunday afternoon ；on the morning of October 10 ； (3) in 用在世纪、年份、季节、月份、上午/下午/晚上等词前。 如： in 2011；in spring ；in January ；in the afternoon；in the daytime； in a day(=during a day)；in summertime；in the twenty-first century (4) in 表示“在„„之后”，后面接时间段，用于将来时态；after 后接时间段时则用于一般过去时，其后接时间点时可用于将来时 。 如： We are going to Beijing in two weeks. We’ll meet after 7:00. He went to America in 2003, and he came back after one year. (5) by表示“在„„之前、到„„时为止”，表示时间上的界限，常与完成时连用。 如：Can you finish the work by tomorrow? By the time this letter reaches you I will have left the country. How many English words had you learned by the end of last term? He ought to have arrived by now/this time. 注意：主句动词为 be 动词时一般不用完成时。 如：By this time next week we shall be in New York. By the time we got home we were tired and hungry. (6) from 常与 to 或till 连用，构成 from„to/till„词组，意为“从„„到„„”，表示时间上的起始与终了。 如：The sports meeting will be held from May 5 to May 8 at school. Wh...
