英语中的介词是连接词汇的重要部分，通常出现在名词、代词或动词之前，表示它们之间的关系。常见的介词包括"At"、"In"、"On"、"By"和"With"，它们在表示时间、位置、状态、方法、手段等方面有各自的用法。要正确使用介词，需要多加练习和实践。
以下是常见的介词以及它们的用法：
- At - 表示时间或位置，例如：
- I will meet you at the library at 3 pm.
- He is sitting at the desk.
- In - 表示时间、位置、状态或条件，例如：
- I was born in 1990.
- She lives in New York.
- I am interested in learning English.
- In case of emergency, call 911.
- On - 表示时间、位置或状态，例如：
- I have a meeting on Monday.
- The book is on the table.
- The TV is on.
- By - 表示方法、手段或时间，例如：
- I will go to work by car.
- He fixed the car by himself.
- We will finish the project by the end of the month.
- With - 表示伴随、附带或使用，例如：
- She went to the party with her best friend.
- The meal came with a side salad.
- I wrote the report with a pen.
