YOU SAID:
My banana was eaten by a kangaroo
INTO JAPANESE
私のバナナはカンガルーに食べられました。
BACK INTO ENGLISH
My bananas was eaten by kangaroos.
INTO JAPANESE
私のバナナは、カンガルーに食べられました。
BACK INTO ENGLISH
My bananas was eaten by kangaroos.
That didn't even make that much sense in English.