YOU SAID:

My banana has gone rotten

INTO JAPANESE

私のバナナが腐ってしまった

BACK INTO ENGLISH

My banana has gone bad.

INTO JAPANESE

私のバナナが腐ってますよ。

BACK INTO ENGLISH

My bananas are gone.

INTO JAPANESE

私のバナナがなくなっています。

BACK INTO ENGLISH

My bananas are gone.