YOU SAID:
why are you coming fast?
INTO JAPANESE
高速にはなぜ来ているか。
BACK INTO ENGLISH
Why come faster?
INTO JAPANESE
なぜ高速化来たか。
BACK INTO ENGLISH
Why did you come faster?
INTO JAPANESE
なぜ早く来たのですか?
BACK INTO ENGLISH
Why did you come early?
INTO JAPANESE
なぜ早く来たの。
BACK INTO ENGLISH
Why did you come early?
That didn't even make that much sense in English.