状语从句是英语中常见的从句类型,包括时间状语从句、原因状语从句、条件状语从句和结果状语从句。这些从句通过修饰主句中的动词、形容词或副词,使句子更加完整、准确。
时间状语从句
时间状语从句用来表示动作发生的时间,通常由 when, while, as, before, after, since, until, till 等引导词引导。
例如:
- When I arrived at the airport, the flight had already left.
- They were watching TV while I was doing my homework.
- As he was leaving the room, he turned off the light.
原因状语从句
原因状语从句表示主句中的动作发生的原因,通常由 because, since, as, for 等引导词引导。
例如:
- Because it was raining heavily, we decided to stay indoors.
- Since she was feeling tired, she went to bed early.
- As he had to catch the early train, he set his alarm for 5am.
条件状语从句
条件状语从句表示主句中的动作发生的条件,通常由 if, unless, provided that, as long as 等引导词引导。
例如:
- If you study hard, you will pass the exam.
- Unless it rains, we will go for a picnic.
- Provided that you arrive on time, we can start the meeting.
结果状语从句
结果状语从句表示主句中的动作产生的结果,通常由 so that, such that, that 等引导词引导。
例如:
- He worked hard so that he could pass the exam.
- She was such a good student that she got a scholarship.
- The weather was so bad that we had to cancel the outdoor activities.