YOU SAID:

they has bigger fish to fry

INTO JAPANESE

彼らには揚げるべき大きな魚がある

BACK INTO ENGLISH

They have a big fish to fry.

INTO JAPANESE

彼らは大きな魚を揚げなければならない。

BACK INTO ENGLISH

They have to fry big fish.

INTO JAPANESE

彼らは大きな魚を揚げなければならない。

BACK INTO ENGLISH

They have to fry big fish.