YOU SAID:

killed the cat, curiosity did.

INTO JAPANESE

猫を殺したが、好奇心は殺さなかった。

BACK INTO ENGLISH

Killed the cat, but not the curiosity.

INTO JAPANESE

猫を殺したが好奇心はなかった

BACK INTO ENGLISH

I killed a cat, but I wasn't curious.

INTO JAPANESE

猫を殺したが興味はなかった

BACK INTO ENGLISH

I killed a cat, but I wasn't interested.

INTO JAPANESE

猫を殺したが興味はなかった

BACK INTO ENGLISH

I killed a cat, but I wasn't interested.