介词
介词：1. 介词又称前置词。
2. 是一种虚词通常不重读，在句子中不独自担任成分。
3．放在名词或具有名词功能的词语之前。
4. 表示其后的名词或具有名词功能的词语与句中其他成分的关系。
EG：He will go to school tomorrow.
She is in the park now.
介词短语的作用：
介词后面的名词、代词或相当于名词的其他词语叫做介词宾语。介词和介词宾语在一起合称为介词短语。
1. 作状语
EG：The soldier fought with great bravery.
She sat in the corner.
He usually gets up at six o’clock.
2. 作后置定语
EG：The girl with long hair is my sister.
The people on the bus were singing.
A friend in need is a friend indeed.
3. 作表语
EG：The girl is like her mother.
She is at school.
The fair girl is on the US team.
3. 作补足语
EG：Make yourlf at home.
We made him out of danger.
I find everything in good condition.
注意：介词短语中，介词后面若是代词，代词用宾格。
EG：He came with them.
常用介词
At
1. 表示位置，在某一个具体的地点。
EG：Let’s meet at the bus station.
I’ll get off at the next stop.
注：(1) 门牌号码用at。
EG：He lives at number 18 Huanghua Road.
(2) 如果不是指所在的地方，而指从事的活动，则这一地点名词前用at。
EG：She is at work.
The boy is at table now.
2. 表示时间点，也指假日时节。
EG：He usually goes to school at 7:00.
The office is clod at the weekend.
3. 表示预定的目的或目标。
EG：She threw a stone at the dog.
She smiled at me.
About
1. 表示位置，指在某一范围里（围绕，在…附近），近似于around。
EG：He walked about the street.
The bee flew about the flowers.
2. 关于。
EG：We talk about the tiger.
I will tell you about the car.
Around
1. 指围绕，美语常用around，英语常用round。
EG：There are many trees around the lake.
All around it is sand.
2. 在各处。
EG：She looked around me.
I show the visitors around the school.
3. 表示时间，在…整个时间。
EG：He walked around the day.
He stayed here around the weeks.
Along
表位置,沿着…，和移动的动词连用,指一种定向路线移动。
EG：I take a walk along the river.
Among
表位置，在…中间（三者或三者以上）。
EG：A bird is singing among the trees.
Against
1. 表示空间，靠着、倚着…。
EG：The boy put my umbrella against the wall.
2. 表示反对、抵抗或逆。
EG：I walked against wind and rain.
We are playing against No.64 Middle School.
After
1. 表示顺序和时间，在…之后。
EG：She goes to the market after school.
Read after me.
2. 指位置时仅表示追逐、追求、追踪、仿照。
EG：Lily ran after the dog.
Who is he after?
What are you after?
Plea make ntences after the model.
Above
1. 表位置，在高于…的水平上。
EG：The water came above our knees.
A plane is flying above the mountains.
2. 在数量方面超过。
EG：The temperature will stay above 0 in the daytime.
We can not accept children above the age of ten.
Across
1. 横过、通过。
EG：There is a bridge across the river.
He walked across the street.
2. 在对面。
EG：My school is across the river.
She lives across the road.
As
1. 表示身份，作为。
EG：We are learning English as a foreign language.
2. 当做。
EG：I respect he as a writer.
Before
1. 表示顺序，在…前面。
EG：He sat before us.
2. 表示时间，在…之前。
EG：You left before 11:00.
注：before和in front of的区别
在表示抽象的场合以及时间之前，用before；具体位置用in front of。
EG：A bright future lies before you.
Behind
1. 表示位置，在…后面。
2. 表示时间，落后于…、晚于…。
EG：The train was ten minutes behind time.
Below
1. 表示相对的位置，在低于…的水平。与above相反。
EG: The kite is flying below the cloud.
2. 表示程度、能力、刻度等低于…
EG：I am below him in sports.
The temperature is three degrees below zero.
Beside
1. 表示方位，在…旁边、附近（强调左右）
EG: Come and sit beside me.
2. 和…相比
EG: Beside your earlier work this piece ems rather disappointing.
这件工作同你早先的工作相比，有些令人失望。
Besides
1. 意为“除……还……”； 或用于否定词之后，表示“除……没有……”
Besides knowing some Ｇreek, she was fluent in Italian.
2. 当用作副词时，意为“而且，此外”。
Peter is our youngest child, and we have three others besides.
彼得是我们最小的孩子，我们另外还有三个孩子。
Between
表示空间\时间。在…两者之间
The moon comes out between the two mountains.
I will phone you between Thursday and Saturday.
By
1. 表示空间, 在…旁边 靠近…
I am sitting by the window.
There is a chair by the table.
2. 表示空间, 经过… 通过…
He came home by Europe.
3. 表示时间，指一件事情出现结果的那一点时间，因为是点时间，不能与持续性动词连用。到…时候
I must finish the work by the end of the month. 我必须在月底之前完成这项工作。
By the end of the last year, they had learned 2,000 words.
到去年年底，他们已经学会了2000个单词。
4. 表示时间，常出现在习语by day, by night . 代替during the day, during the night.
She sleeps by day and works by night. 她白天睡觉，夜晚工作。
5. 表示交通工具、通过…行为和施动者、用…方法。
He goes to school by bus.
The gloves were made by hand.
