为什么he not read such books as he can't 是对的,不是应该he don't read

如果是一句简单句的话,he don't read such books as he can't显然是正确的如果是复合句的一部分（从句）的话,he not read such books as he can't是可能成立的e。g:The teacher suggest/advise that he (should)not read such books as he can't老师建议他别去看这种书。这是表示建议、意见的动词如：suggest\recommend\advise之后加宾语从句的虚拟语气用法,简单来说就是这种词后面的宾语从句的谓语必定是should do而且should常常被省略。