YOU SAID:
The cat is sitting on the rooftop
INTO JAPANESE
猫は屋上に座っています。
BACK INTO ENGLISH
Cat is sitting on the roof.
INTO JAPANESE
猫は屋根の上に座っている。
BACK INTO ENGLISH
The cat is sitting on the roof.
INTO JAPANESE
猫は屋根の上に座っています。
BACK INTO ENGLISH
The cat is sitting on the roof.
That didn't even make that much sense in English.