오전 보통 or 보통 오전?

Hi, I'm studying about 시간 so I'm learning new vocabulary.
I search on a translator if 오전 보통 and 보통 오전 have sense because I don't know which one is correct but both of them have...
Now I'm confused...

I'd like to know if both are correct or only one and maybe which one is more common.
Thanks in advance.

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A: 한국어를 언제 공부해?

B: 보통 오전에 (공부)해. (or 오전에 보통 해.) '보통 오전(에)' sounds more natural.

    보통 오전이야. (ㅇ)    오전 보통이야.(X)

By the way, you posted it on the English board, not Korean.