YOU SAID:

hello my fish has to go on a walk

INTO JAPANESE

こんにちは私の魚は散歩に行かなければなりません

BACK INTO ENGLISH

Hello my fish do not have to go for a walk

INTO JAPANESE

こんにちは私の魚は散歩に行く必要はありません

BACK INTO ENGLISH

Hi my fish don't have to go for a walk

INTO JAPANESE

こんにちは私の魚は散歩に行く必要はありません

BACK INTO ENGLISH

Hi my fish don't have to go for a walk