时间状语从句是英语语法中的一个重要部分，用于描述动作或状态发生的时间背景。时间状语从句通常由从属连词引导，这些连词在句子中起到连接主句和从句的作用，使句子结构更加完整，逻辑更加清晰。常见的时间状语从句连接词包括：
when ：用于描述一个事件发生的具体时间点，或主句的动作和从句的动作同时发生。while：
用于描述两个同时进行的动作或事件，或主从句的动作发生在主句的动作之后。
as：
引导的时间状语从句表示两个动作或事件同时发生，侧重于表示主句和从句的动作并相发生。
before：
用于描述一个事件发生之前的时间。
after：
用于描述一个事件发生之后的时间。
until/till：
用于描述一个动作或事件持续到某个时间点。
since：
用于描述一个动作或事件开始的时间点。
as soon as：
用于描述一个动作或事件发生后立即发生的另一个动作或事件。
在时间状语从句中，主句和从句的时态应该相对应，以便正确地表示时间关系。例如，如果主句是一般将来时，从句通常用一般现在时表示将来意义。
时间状语从句可以放在句首或句尾，但要注意，如果从句在主句前面，那么两者之间要用分号隔开。
When
When I arrived at the station, the train had already left. [主先从后]
When she was working in the garden, her son woke up. [同时]
While
While he was reading the newspaper, she was cooking dinner. [同时]
While I was studying, my brother was playing video games. [同时]
As
As soon as she finished her homework, she went out to play. [一……就……]
As she was walking down the street, she saw an old friend. [同时]
Before
Before the meeting started, everyone had already arrived. [在……之前]
Before she left home, she checked the weather forecast. [在……之前]
After
After the movie ended, the audience started to leave. [在……之后]
After she finished her work, she went to bed early. [在……之后]
Until/Till
They waited until the sun came up. [直到……为止]
She studied until midnight. [直到……为止]
Since
Since she was a child, she has always been interested in music. [自从……以来]
Since he moved to the city, he has never been back to his hometown. [自从……以来]
As soon as
As soon as she heard the news, she started crying. [一……就……]
As soon as he finished his homework, he joined his friends for dinner. [一……就……]
这些例子展示了不同时间状语从句连词的使用方法和它们在句子中的具体应用。