YOU SAID:

a fish is not swimming in a hottub

INTO JAPANESE

湯船で泳いでいる魚ではない

BACK INTO ENGLISH

It's not a fish swimming in the hot tub.

INTO JAPANESE

湯船で泳ぐ魚ではない。

BACK INTO ENGLISH

It is not a fish swimming in the hot tub.

INTO JAPANESE

湯船で泳ぐ魚ではありません。

BACK INTO ENGLISH

It is not a fish swimming in the hot tub.