一. 介詞by的用法
1.意為“在……旁”，“靠近”。
Some are singing and dancing under a big tree. Some are drawing by the lake.
有的在大樹下唱歌跳舞。有的在湖邊畫畫兒。
2. 意為“不遲於”，“到……時為止”。
Your son will be all right by supper time.
你的兒子在晚飯前會好的。
How many English songs had you learned by the end of last term?
到上個學期末你們已經學了多少首英語歌曲?
3. 表示方法、手段,可譯作“靠”、“用”、“憑藉”、“通過”、“乘坐”等。
The monkey was hanging from the tree by his tail and laughing.
猴子用尾巴吊在樹上哈哈大笑。
The boy’s father was so thankful that he taught Edison how to send messages by
railway telegraph.
孩子的父親是那麼的感激,於是他教愛迪生怎樣通過鐵路電報來傳達信息。
4. 表示“逐個”，“逐批”的意思。
One by one they went past the table in the dark.
他們一個一個得在黑暗中經過這張桌子。
5. 表示“根據”，“按照”的意思。
What time is it by your watch?
你的表幾點了?
6. 和take , hold等動詞連用，說明接觸身體的某一部分。
I took him by the hand.
我拉住了他的手。
7. 用於被動句中，表示行為主體,常譯作“被”、“由”等。
English is spoken by many people.
英語被許多人說。（即“許多人講英語。”）