YOU SAID:
Can you please buy a rotten banana from the store
INTO JAPANESE
あなたは店から腐ったバナナを買ってください。
BACK INTO ENGLISH
You buy a rotten banana from the store.
INTO JAPANESE
あなたは店から腐ったバナナを買います。
BACK INTO ENGLISH
You buy a rotten banana from the store.
That didn't even make that much sense in English.