YOU SAID:

big fish fish the little fish in the cardboard fish box

INTO JAPANESE

大きな魚は段ボールの魚箱の中の小さな魚

BACK INTO ENGLISH

The big fish is the small fish in the cardboard fish box

INTO JAPANESE

大きな魚は段ボールの魚箱の中の小さな魚です

BACK INTO ENGLISH

The big fish is the small fish in the cardboard fish box