YOU SAID:

the fat rat sat on a cat

INTO JAPANESE

太ったネズミは猫の上に座っていました

BACK INTO ENGLISH

The fat mouse was sitting on the cat

INTO JAPANESE

太ったネズミが猫の上に座っていた

BACK INTO ENGLISH

A fat mouse was sitting on a cat

INTO JAPANESE

太ったネズミが猫の上に座っていた

BACK INTO ENGLISH

A fat mouse was sitting on a cat