老师，你能否给比较分句和名词性关系从句下个明确的概念？谢谢!
比较分句：由从属关联词as/than引导的具备比较意义的分句。（之所以用从属关联词这个术语，是为了防止as/than是从属连词还是代词/副词的争议。）比较分句可以作形容词或副词的补足语、作句子或句子一部分的补充语、作方法状语、或作名词的修饰语等。
主句，as we know. (补充语）
She is beautiful, as is her sister. （补充语）
She is as beartiful as her sister is. (形容词的补足语）
This is the same bag as I lost yesterday. (形容词的补足语）
She runs as fast as I do. (副词的补足语）
Do as I said. (方法状语）
Life as we know it needs water and air to survive. （名词的限制性修饰语）
传统语法对以上as分句有不一样的剖析。
名词性关系分句：由融合型关系代词/关系副词引导的名词性从句。
This is what I bought yesterday.
Whoever said that was lying.
This is where I was born.
