介词 preposition1.介词：是用表明名词、代词等于句中其他词的关系的词。介词是虚词，不能在句子中独立充当成分。它总是用于名词、代词、或相当于名词的其它词类或短语从句前。2.介词的分类：（1）表示地点、方位的介词 （2）时间介词 （3）手段介词 （4）其他等（1）时间介词： 表示年、月、日、时刻等用at，in，onA at用于表示时刻、时刻的某一点 e.g. at eleven oclock at noon at presentB on用于表示某日，某天的上午、下午、晚上 e.g. on Saturday On March 8thC in用于表示一段时间或季节 e.g. in December in spring 表示前后用before，afterA. before:在.之前 e.g. Come and see me tomorrow at any time before eleven a.m.B. after:在.之后 e.g. Spring comes after winter. 表示期限等用by，until，tillA. by:在.之前，不迟于 e.g. By the time I arrived, she had already gone.B. Until，till:直到.为止 e.g. The radio worked all night till last night. 表示期间等用for，during，through，betweenA. for:达.之久（表示过了多少时间） e.g. My Johnson stayed in China for 2 weeks.B. during:在时期当中 e.g. He woke many times during the night.C. through:在整整一段时间内 e.g. She sat there ,alone, all through that day.D. between:在（两个时间）之间，突出时间的起点和终点，相当于from.toe.g. He kept on working between seven and twelve last night. 表示时间的起点用from，sinceA. from:从.起 e.g. From sunrise to sunset he waited.B. since:自从.以来 e.g. Since my last letter I have heard from him twice. 表示时间的经过等用in，withinA. in:过.后（未来时间） e.g. I heard that she would be back in a month.B. within:以内，不超过 e.g. He will arrive within an hour.【in , at , on 作为时间介词的区别】【in】 1 表示在较长的时间里（如周月份季节年份世纪等）。如：in a week； in May； in springsummerautumnwinter； in 2008； in the 1990s等。 2 表示在上午、下午或晚上。如：in the morningafternoonevening。 3 in the daytime（在白天） 属于固定搭配，指从日出到日落这一段时间 反义词in the night4 “in 一段时间”表示“多久以后以内”，常与将来时连用。如：in half an hour； in ten minutes； in a few days等。 【on】 1 表示在具体的某一天（如日期、生日、节日或星期几）。如：on May 4th， 1919； on Monday； on Teachers Day； on my birthday； on that day等。 2 表示某一天的上午、下午或晚上。如：on the morning of July 2； on Sunday afternoon； on a cold winter evening等。 【at】1 表示在某一具体时刻，即几点几分。如：at six oclock； at half past nine； at a quarter to six； at this time等。 2 表示在某一短暂的时间。如：at noon； at this moment； at the end of a year； at the start of the concert等。【注意】下列表示时间的状语前不加介词1、当有today, yesterday, tomorrow, tonight, yesterday/tomorrow morning(afternoon, evening)等时间状语时，其前不用介词。（1）There was a football match yesterday evening.（2）They will go to the zoo tomorrow.2、由this, that, these, those等构成的短语前不用介词。（1）Ill visit my grandparents this week.（2）They are picking apples on the farm these days.3、由形容词last，next等指示代词修饰的名词词组用作时间状语时不用介词。 （1）I saw him in the street sometime last week.（2）Please come to school earlier next time.4、在以“the day (week, month, year) +before/after”构成的时间状语前不用介词。（1）Where did you go the day before yesterday? （2）Theyll have a party the day after tomorrow.5、由every, each等表示频率的副词构成的短语用做时间状语时，其前不用介词。（1）Do you watch TV every day? （2）They go to school by bike each day.6、由on引出的特定日子，可以省略介词on。例如：I can see him (on) New Years Day.（2）表示地点、方位的介词：指表示事物之间空间关系和方向的介词。常用的词有：in, on, at, under, outside, beside, behind, in front of，opposite等。1）in , at 作为地点、方位介词的区别at 表示在小地方 e.g. We always meet at the bus station. 表示某一点位置 e.g. We lived at No.29 Beijing Road.in 表示在大地方 e.g. He lived in Guangzhou. 表示在里面 e.g. The book is in the desk.2）In 和on 的区别on the tree 表示枝、叶、果实等长在树上There are some apples on the tree.in the tree 表示人或其他东西在树上There are some monkeys in the tree.on the wall 表示东西黏贴或挂在“墙上”There is a picture on the wall.in the wall 表示门、窗等嵌在墙上There is a hole in the wall.(3)手段介词：指做某件事所使用的方法和手段的介词。常用的方式介词有：with, by, in等。e.g. We see with our eyes.I usually go to school by bike.Can you say it in English?(4)其他介词的用法。 表示“由.制成”的介词:of，fromA. of：表示成品看得出原材料 e.g. The table is made of wood.B. from：表示成品看不出原材料 e.g. This kind of paper is made from wood. 表示其他的介词:without，like，as，against等A. without：没有 e.g. He hurried to the office without having his breakfast.B. like：像，如，跟一样 e.g. Whats he like?C. as：作为 e.g. He is famous as a scientist here.D. against：靠着，反对 e.g. Dont stand against the door. e.g. Dr Sun Yetsan was against the emperor.Eabout a. 表示大约时间： Is about six oclock now. 现在大约6点钟了。 b. 关于，对于： We are talking about the news. 我们正在谈论新闻。【拓展】：介词 for 的用法小结1. 表示“当作、作为”。如:I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。What will we have for supper? 我们晚餐吃什么?2. 表示理由或原因,意为“因为、由于”。如:Thank you for helping me with my English. 谢谢你帮我学习英语。Thank you for your last letter. 谢谢你上次的来信。Thank you for teaching us so well. 感谢你如此尽心地教我们。3. 表示动作的对象或接受者,意为“给”、“对 (而言)”。如:Let me pick it up for you. 让我为你捡起来。Watching TV too much is bad for your health. 看电视太多有害于你的健康。4. 表示时间、距离,意为“计、达”。如:I usually do the running for an hour in the morning. 我早晨通常跑步一小时。We will stay there for two days. 我们将在那里逗留两天。5. 表示去向、目的,意为“向、往、取、买”等。如:Lets go for a walk. 我们出去散步吧。I came here for my schoolbag.我来这儿取书包。I paid twenty yuan for the dictionary. 我花了20元买这本词典。6. 表示所属关系或用途,意为“为、适于的”。如:Its tim