YOU SAID:
Did you every saw so so fast dog?
INTO JAPANESE
こんなに速い犬を見たことがありますか?
BACK INTO ENGLISH
Have you ever seen a dog so fast?
INTO JAPANESE
こんなに速く犬を見たことがありますか?
BACK INTO ENGLISH
Have you ever seen a dog so fast?
That didn't even make that much sense in English.