how能引导什么从句？

除了不能引导定语从句，how可以引导其他5类从句，即主语从句、宾语从句、同位语从句、表语从句和状语从句。

• I don’t know how you did it. 宾语从句
• How you did it is none of my business. 主语从句
• This is how you did it. 表语从句
• We have no idea how you did it. 同位语从句

how引导状语从句不典型，不太正式，通常指这样的：