YOU SAID:

i speak if i am dumb.

INTO JAPANESE

私がばかだと私は話す。

BACK INTO ENGLISH

I will talk that I am stupid.

INTO JAPANESE

私は私がばかだと話します。

BACK INTO ENGLISH

I will tell you I am stupid.

INTO JAPANESE

私はあなたが馬鹿だと伝えます。

BACK INTO ENGLISH

I will tell you that you are stupid.

INTO JAPANESE

あなたは愚かだと私はあなたに伝えます。

BACK INTO ENGLISH

I will tell you that you are stupid.