some后面可以加big原因是some ，不定代词，表示一些。

big，形容词/副词，意思是adj. （尺寸、数量、规模或年龄）大的；重大的，严重的……形容词要放在不定代词的后面，例如Obviously, they've had sponsorship from some big companies.But the study had some big flaws.所以说some 后能加big