搞懂状语从句的核心在于记住引导各类状语从句的连词。在9种状语从句中，尤以引导时间状语从句的连词数量最多，又牵扯到时态的问题，所以用法最复杂。最常见的10个连词如下图：
1类一…就…：
除了我们最熟悉的as soon as外，以下10个词或句式同样可以表“一…就…”。
其中，1once（一旦）+ 3“ly” （立即，立刻）+4the+n（在那一分那一秒那一刻）的用法与as soon as（和…一样快）相同。注意理解这些词的本义是如何引申出“一…就…”的。
例句：我一到家的（时候）天就开始下雨。
It began to rain as soon as I arrived home.
=It began to rain immediately/instantly/ directly I arrived home.（我一到家立刻开始下）
=It began to rain the minute/second/moment/instant I arrived home.（在我到家那一刻开始下）
2倒装的用法参考前文英语部分倒装的15种用法=1只有+2也不+3虚拟+4如此+5否定
=Hardly had I arrived home when it began to rain.
=No sooner had I arrived home than it began to rain.
2组相反：
since与until(till)相反，before与after相反，并且这4个连词都可以作介词。注意下方例句，连词+句子，而介词+名词性成分。
It is/has been 10 years since he moved here/since 2009
He didn't go to bed until his mother told him a story/until 11 p.m.
He gave away all his money before he died=before his death.
He became a teacher after he graduated=after his graduation
3个当…时：
when和while关于动作延续性的用法相信大家都很熟了。我们来看更难的用法。
1.when：正在这时……，这时突然……
I was reading a novel when the teacher came in.
2. while：然而，位于句中表对比。
He love dogs, but he doesn't want to keep one.（同一个人前后行为的转折）
Some people love doges while others hate them.（两类人行为的对比）
3. As the time goes by =with time going by（as是连词+句子，with是介词构成with复合结构）
4个次：
注意下面四个例句中主句和从句的时态。
The first time I met her, I fell in love with her.（主过从过）
Every/Each time I meet her, I fall in love again.（一般现在）
Next time I meet her, I will love her more.（主将从现）
Last time I met her, she was only 18.（主过从过）
注意：另外还有by the time，主句要用完成时。
By the time I met her again, she had got married.（到过去为止，用过去完成）
By the time Summer comes, I will have lost much weight.（到将来为止，用将来完成）
关于其余8种状语从句的连词，后文再作详细解析。