I. 介词的概念
介词是一种用来表示词与词, 词与句之间的关系的词。在句中不能单独作句子成分。介词后面一般有名词代词或相当于名词的其他词类，短语或从句作它的宾语。介词和它的宾语构成介词词组，在句中作状语，表语，补语或介词宾语。
II. 牢记口诀
介词口诀：自从以当为按照，由于对于为了到；和跟把比在关于，除了同对向往朝；用在名词代词前，修饰动形要记牢。
III. 介词归类大全
一、表示地理位置的介词：
(1)at ,in, on, to
at (1)表示在小地方; (2)表示“在……附近，旁边”
in (1)表示 在大地方; (2)表示“在…范围之内”。
on 表示毗邻，接壤
to 表示在……范围外，不强调是否接壤
例句：He arrived at the station at ten.
He is sitting at the desk.
He arrived in Shanghai yesterday.
Jiangsu lies in the east of China.
Russia lies on the north of China.
Fujian is to the south of Jiangsu Province.
(2)above, over, on 在……上
above 指在……上方,不强调是否垂直，与 below相对；
over指垂直的上方,与under相对,但over与物体有一定的空间，不直接接触。
on表示某物体上面并与之接触。
例句：The bird is flying above my head.
There is a bridge over the river.
He put his watch on the desk.
(3)below, under 在……下面
under表示在…正下方
below表示在……下，不一定在正下方
例句 There is a cat under the table.
Please write your name below the line.
二、表示时间的介词：
(1)in , on，at 在……时
in表示较长时间，如世纪、朝代、时代、年、季节、月及一般（非特指）的早、中、晚等。
如：in the 20th century, in the 1950s, in 1989, in summer, in January,
in the morning, in the night, in one’s life , in one’s thirties等。
on表示具体某一天及某一天的早、中、晚。
如：on May 1st, on Monday, on New Year’s Day, on a cold night
in January, on a fine morning, on Sunday afternoon等。
at表示某一时刻或较短暂的时间，或泛指圣诞节，复活节等。
如: at 3:20, at this time of year, at the beginning of, at the end of …,
at the age of …, at Christmas， at night, at noon, at this moment等。
注意：在last, next, this, that, some, every 等词之前一律不用介词。如：We meet every day.
(2)in, after 在……之后
“in +段时间”表示将来的一段时间以后；
“after+段时间”表示过去的一段时间以后；
“after+将来点时间”表示将来的某一时刻以后。
例句：My mother will come back in three or four days.
He arrived after five months.
She will appear after five o’clock this afternoon.
(3)from, since 自从……
from仅说明什么时候开始，不说明某动作或情况持续多久；
since表示某动作或情况持续至说话时刻，通常与完成时连用。
例句：He studied the piano from the age of three.
They have lived here since 1978.
(4)after, behind 在……之后
after主要用于表示时间；
behind主要用于表示位置。
例句：We shall leave after lunch.
Lucy is hiding behind an old house.
三、表运动方向的介词：
across, through 通过，穿过
across表示横过,即从物体表面通过，与on有关；
through穿过,即从物体内部穿过，与in有关。
例句：She swam across the river.
He walked through the forest.
四、表示“在……之间”的介词：
between, among
between指在两个人或两个事物之间；
among指在三个或三个以上的人或事物之间。
例句：There is a football match between Class One and Class Two on the playground.
The teacher is standing among the students.
五、表示其他意义的介词：
(1)on ,about 关于
on 表示这本书，这篇文章或演说是严肃的，或学术性的，可供专门研究这一问题的人阅读；
about表示内容较为普通，不那么正式。
例句：There will be a lecture on economics this afternoon.
He is writing a book on cooking.
He told me a lot about his life in the summer vocation.
(2)by, with, in 表示方法、手段、工具
by 以……方法、手段或泛指某种交通工具；
with 表示用 …工具、手段，一般接具体的工具和手段；
in 表示用…方式，用…语言(语调、笔墨、颜色)等；
例句：He makes a living by selling newspapers.
He broke the window with a stone.
The foreigner spoke to us in English.
(3)except, besides 除了
except 除……之外，不包括在内；
besides 除……之外，包括在内。
例句：Except Mr. Wang, we went to see the film.(王先生没去)
Besides Mr. Wang, we also went to see the film.(王先生也去了)
巩固练习：
1. Taiwan is ________ the southeast of China.（in, on, to）
2. Go _________ the bridge _________ the river, you’ll find the shop.（across, through; over, above）
3. I go to school __________7:30 every morning.（in, on, at）
4. He would like to meet her __________8:00 and 9:00 tomorrow morning.（between, among ）
5. The Greens have lived in China ________ three years.（in, for, after）
6. We go to school every day ________ Saturday and Sunday.（except, besides）
7. He wrote the letter _________ ink.（by, with ,in）
8. She returned to her country _________five years.（in, after, for）
9. There is a big tree _________ our classroom.（after, behind）
10. I usually go to work _________ bike.（by, on, with）
其他其它常用介词
介词在英语词汇中所占比例很小，但它们的用法却非常灵活,复杂。下列为常用介词及含义：
about 关于,附近,大约,周围,随身.
I have bought a book about Shakespearean. 我买了一本有关莎士比亚的书。
There are about fifteen trees in the picture. 图片里大约有十五棵树。
above 在....上,高出,以上,超过,在...上游.
The plane is flying above the clouds. 飞机在云上飞行。
I think the man is above sixty years old. 我想那人有六十多岁了。
across 横过,对面,交*,在...的对面.
Can you swim across the river？ 你能游过河吗？
We live across the street. 我们住在街的对面。
after 在...后面,依照.
He went home after school. 他放学后就回家了。
Read after me, please. 请跟我朗读。
against 撞到，靠着,反对,违背,
The car hit against the tree. 汽车撞了树。
He is standing against the wall. 他靠墙站着。
along 沿着,顺着.
They are walking along the river. 他们沿着河行走。
among 在...当中.
He is the tallest among them. 他是他们当中个子最高的。
around 在...的周围,在...那一边.
They sat around the table talking the news. 他们绕桌而坐谈论新闻。
There is a drugstore around the corner. 拐角处有一家药店。
as 作为.
He doesn't like people treat him as a child. 他不喜欢人们把他当小孩子对待。
at 在...时刻,在...点钟,在...岁时, 向，在...之中，按...速度,值(卖)...钱,
He always gets up at six in the morning. 他时常早上六点钟起床。
He shot at the bird but missed it. 他向鸟射击，但是没射中。
The car goes at eighty miles an hour. 汽车以每小时八十公里的速度行驶。
before 在...的前面(位置),在...之前(时间)
He took a picture before the car. 他在汽车前照了张照片。
He can't finish his work before supper. 晚饭前他完不成工作。
behind 在...的后面(位置), 落后于，不如， 迟于,晚于(时间)
Are there any brooms behind the door. 门后有扫帚吗？
All of us are behind him in mathematics. 我们数学都不如他。
below 在...之下,低于,
There are four lights below the ceiling. 天花板下面有四盏灯。
The murderer run away below the police's eyes. 杀人犯从警察眼皮底下跑了。
beside 在...的旁边,在...之外,与...相比.
He found the body beside the river. 他在河边发现了尸体。
Beside yours， my computer is too slow. 与你的计算机速度相比，我的就慢多了。
besides 除...之外,
We are all here besides Bowe. 除鲍外，我们也都来了。
between 在...两者之间,
The relations between the two countries has improved since then. 两国的关系从那以后得到了改善。
beyond 在...那边,
The shop you are looking for is beyond the street, you can't miss it. 你要找的商店在街的那边，你不会找不到的。
but 除去.
He has nothing but money. 他除钱以外什么都没有。
by 被..., 在...的近旁 , 在...之前, 不迟于, 以...为手段。
The classroom was cleaned by the students. 教室由学生们打扫干净了。
Miss Lucy came to China by air. 露西小姐是乘飞机来中国的。
down 沿着...望下。
She walked down the street. 她沿着街道走。
during 在...期间,在...时候。
During the holiday, we went to the south. 我们假期去了南方。
except 除...之外。
He knows nothing except English. 他除英语以外什么都不知道。
for 为..., 因为..., 至于... 。
He works for this company. 他为这家公司工作。
She came back to the classroom for she had left her books in the classroom. 她返回到教室是因为把书留在了那里。
from 从..., 来自..., 因为...。
Where are you from? 你是哪里人？
He died from an accident. 他死于一场事故。
in 在..., 在...之内，从事于..., 按照..., 穿着...。
He was born in 1992. 他生于1992年。
I could finish the program in two weeks. 我可以用两周时间完成这个项目。
He spend less time in reading. 他读书时间很少。
The man in black jacket is our teacher. 穿黑夹克的那个人是我们的老师。
like 象...，如同...。
The twins are like their father. 双胞胎像他们的父亲。
near 靠近....。
There are some flowers near the house. 房子附近有一些花。
of ...的，属于...。
This is a map of China. 这是一张中国地图。
off 离开...，在...之外。
The young man got off the train quickly. 那个年青人很快下了火车。
I live in a village a little way off the main road. 我住在离大路不远的一个村庄里。
on 在...之上。
My book is on the table. 我的书在桌子上。
out of 从...出来，在...之外。
The dog run out of the house. 狗从房子里跑出来。
outside ... 外边.
They are waiting outside the gate. 他们在门外等着。
over 在...之上，遍于...之上，越过...。
There is a light over the desk. 桌子上方有盏灯。
He is over sixty years old. 他有六十多岁。
past 越过...，过...，超越...。
The students walked past the post office. 学生们走过了邮局。
It is ten past two. 现在是两点十分。
round 围着...，绕过...，在...周围。
We sat round the table. 我们围着桌子坐下。
The earth goes round the sun. 地球绕着太阳转。
since 自... 以后，自...以来。
He has made great progress in English since he came into the college. 从他来到大学后，他的英语有了很大进步。
through 经过...，穿过...。
They went through the forest. 他们穿过了森林。
throughout 遍及...，在各处。
The police searched for the criminal throughout the mountain. 警察搜山寻找犯人。
till 直到...，在...以前。
He didn't come back till eleven o'clock. 他直到十一点钟才回来。
We'll be home till six. 六点以前我们都会在家。
to 到...，向...，趋于。
How long is it from here to the station？ 从这儿到车站有多远？
under 在...之下，低于。
There are some footballs under the bed. 床底下有几颗足球。
These students are under seventeen years old. 这些学生们不到十七岁。
until 直到，在...以前，
Please wait for us until we come back. 请等着我们回来。
It was not until last week that I handed in mathematics paper. 直到上周，我才交了数学论文。
up 在...上面，在...上。
He went up the stairs. 他上了楼梯。
upon 在...之上，迫近...。
It's not polite to look down upon him. 蔑视他是不礼貌的。
within 在...之内。
You must finish the work within two weeks. 你必须两周内完成这项工作。
without 没有，不，在...之外。
We can't do it better without your help. 没有你的帮助，我们就做不好。
We couldn't live without air and water. 没有空气和水，我们就不可能生存。