YOU SAID:

I think my brother is dumb.

INTO JAPANESE

私は弟が馬鹿だと思う。

BACK INTO ENGLISH

I think that brother is stupid.

INTO JAPANESE

私は弟がばかだと思う。

BACK INTO ENGLISH

I think my brother is stupid.

INTO JAPANESE

私は弟がばかだと思う。

BACK INTO ENGLISH

I think my brother is stupid.