He is not so good a student as you. 是对的.他不像你一样是个好学生.
不过,这好像是否定句?呵so +adj. +a/an +n.(single) +as 能用在肯定句中吗？ eg. He isso good a student as you.好像没有这样的用法的呢。一般都是not so good as 的。