"However" 可以引导两种从句：
名词性从句
"However" 可以引导名词性从句，相当于 "anything that"，意思是“所……的任何事情”，在语气上比 "what" 更加强调。
让步状语从句
"However" 作为连词时，引导让步状语从句，意思是“不管怎么样”、“无论如何”，相当于 "no matter what" 或 "whatever"。在从句中，"however" 可以作主语、宾语、表语或定语。
示例
引导名词性从句
I like the book however much it costs.
引导让步状语从句
However hard he tried, he couldn't solve the problem.
However fast she runs, she can't catch up with the others.
建议
在使用 "however" 时，要注意其后面所跟的词语的词性，以确保句子结构的正确性。
"However" 通常用于表达转折或对比，因此在使用时要确保前后文在逻辑上形成对比或转折关系。