by是个很常用的介词(有时也用作副词),在初中英语中的用法有以下几种:

1.意为“在……旁”、“靠近”。例如:

Some are singing and dancing under a big tree. Some are drawing by the lake.

有的在大树下唱歌跳舞,有的在湖边画画儿。

2.意为“不迟于”、“到……时为止”。例如:

Your son will be all right by supper time. 你的儿子在晚饭前会好的。

How many English songs had you learned by the end of last term?

到上个学期末你们已经学了多少首英语歌曲?

3.表示方法、手段,可译作“靠”、“用”、“凭借”、“通过”、“乘坐”等。例如:

The monkey was hanging from the tree by his tail and laughing.

猴子用尾巴吊在树上哈哈大笑。

The boys father was so thankful that he taught Edison how to send messages by railway telegraph. 孩子的父亲是那么的感激,于是他教爱迪生怎样通过铁路电报来传达讯息。

4.表示“逐个”、“逐批”的意思。例如:

One by one they went past the table in the dark. 他们一个一个地在黑暗中经过这张桌子。

5.表示“根据”、“按照”的意思。例如:

What time is it by your watch? 你的表几点了?

6.和take, hold等动词连用,说明接触身体的某一部分。例如:

I took him by the hand. 我拉住了他的手。

7.用于被动句中,引出行为主体,常译作“被”、“由”等。例如:

English is spoken by many people. 英语被许多人所说。(即“许多人讲英语。”)

8.组成其它短语。

1) by the way:意为“顺便说”、“顺便问一下”,常作插入语。例如:

By the way, wheres Li Ping, do you know? 顺便问一下,李平在哪儿,你知道吗?

2) by oneself:意为“单独”、“自行”。例如:

I cant leave her by herself. 我不能把她单独留下。

3) by and by:意为“不久以后”、“不一会儿”。例如:

But by and by, more and more people began to study English.

但是不久以后,越来越多的人开始学英语了。

【小试牛刀】根据汉语意思完成句子(每空填一个词)。

1. 他每天乘公共汽车上班。

He goes to work ____ ____ every day.

2. 顺便问一下,你认识杰克吗?

____ ____ ____, do you know Jack?

3. 孩子们两个两个地在操场上跑步。

The children are running on the playground ____ ____ ____.

4. 我将在本月底以前写完这本书。

I'll finish writing the book ____ ____ ____ of this month.

5. 河边有棵大树。

There's a tall tree ____ ____ ____.

6. 爷爷病了,你不能把他单独留在家里。

Grandpa is ill. You can't leave him ____ ____ at home.

7. 我的表现在是三点钟。

It's three o'clock ____ ____ ____.

8. 不久以后,我们都学会了怎样做飞机模型。

____ ____ ____, we all learned how to make model planes.

[Key:1.by bus 2.By the way 3.two by two 4.by the end 5.by the river 6.by himself 7.by my watch 8.By and by]