8.among用于表示三者之间, between用于表示两者之间, 或三者以上的 “两两之间”

　　　　 a. The distance between Beijing and Taiyuan is about 500 kilometers.

　　　　 b. I found them among the crowd.

7.表示 “在…上, 在…下时”, on / beneath表示与表面接触, over / under表示不与表面接触, 垂直在上或在下, above / below表示不与表面接触, 在上或在下, 不一定垂直

　　 　　　a. The boy is standing on the table.

　　　　 b. Put some straw beneath the carpet.

　　　　 c. Now the bridge is under the plane.现在桥在飞机的正下方

　　　　 d. All the fields are below the plane.

6.表示相对方位时, in表示在内部, to表示在外部, on表示接壤

　　　　 a. Japan is to the east of China.

　　　　 b. The Pacific is on the east of China.

　　　　 c. Shanghai is in the east of China.

5.表示 “穿过”时, across表示动作在表面或近似表面上进行, through表示动作在空间里进行

　　　　 a. The old man came across the street himself.

　　　　 b. They went through the forest three days later.

4.表示在“某街道”时, 其前有门牌号时, 介词用at; 不标明门牌号时, 英国英语用in, 美国英语用on

　　　　 a. My uncle lives at 105 Beijing street.

　　　　 b. She lives in / on Wuyi Street.

3.in / after在表示“在(一段时间)之后”时, in常与将来时连用; after常与过去时连用

　　　　 a. The doctor will be here in ten minutes.

　　　　 b. He said he would be back in a few days.

　　　　 c. He came back after two hours.

2.since / for表时间时的区别: since后接表示起点时间的词;　 for后接表示段时间的词

a. I have been living here since 1972.

　　 b. I have lived here for 32 years.

2.on / in表时间的区别:

①.表示在具体的某一天用介词on, 如: on Tuesday, on September 29th; 表示在上午, 下午, 中午, 晚上一般应用介词in, 但表示在具体的某一天或有具体某特征的某一天的上午, 下午, 中午, 晚上用介词on, 如: on the morning of our sports meet, on the afternoon of the rainy day.

②.表示在某假日时, 如果假日是具体的日子, 则用介词on, 如果指的是 “时节”, 则要用at, 如: at the weekend, at Christmas, at Midsummer, at Easter在复活节

　 　　　　a. Without a word he left the room.

　　　　 b. He looked at me without expression.

　　　　 c. He had advised her to come without delay.

　　　　 d. There is no fire without some smoke.

　　　　 e. She oughtn’t to go off like that without telling me.

　　　　 f. Without waiting for any reply, he left the room.

　　　　 g. Nobody can speak English without making mistakes.

　　　　 h. His face was without expression.

应注意的问题

1. this / that / next / last / yesterday / tomorrow / one / every / each / some / any / all +表示时间的名词时, 其前不用介词on或in等表示在这一时间里

　　　　 a. They are planning to visit China next year.

　　　　 b. I received a letter from him yesterday morning.

　　　　 c. Each morning he would get up early and walk in the woods.

　　　　 d. He worked deep into night every day.

　　 ①.在…以内(里面)

　　　　 a. They were within shouting distance.

　　　　 b. All was quiet within the house.

　　　　 c. The farmhouse is within five miles from here.

　　 ②.在(一段时间)内

　　　　 a. I shall be back within an hour.

　　　　 b. The roof should be repaired within two days.

　　　　 c. He died within a few days of his hundredth birthday.

③.在…内心里

　　　　 a. He could feel deep disappointment within him.

　　 ④词组和固定搭配: within limits在...限度内; with reach够得着, 能得到