not so ... as ...NOT formal used in comparisons to say that something or someone has less of a particular quality than another person or thing 不如…这么…，不像…那样… The bed was not so comfortable as his own. 这张床没有他自己的床舒服。
5 GRAMMAR 语法Do not use so in comparisons without 'not'. Use as . 表示比较时如没有 not 则不要用 so, 用 as
Your handwriting is as bad as mine (NOT 不说 so bad as mine).你的字写得和我一样差。
n GrammarIn comparisons without ‘not’, you say as ... as: Your writing is as bad as mine. 你的字写得和我一样差。
✗Don’t say: Your writing is so bad as mine. → not so ... as ... at so1(7)