YOU SAID:
I have a cat that is grey
INTO JAPANESE
私はグレーの猫があります。
BACK INTO ENGLISH
I have a grey cat.
INTO JAPANESE
私は猫を飼っている。
BACK INTO ENGLISH
I have a cat.
INTO JAPANESE
私は猫を飼っている。
BACK INTO ENGLISH
I have a cat.
That didn't even make that much sense in English.