YOU SAID:
What's up? I haven't seen you in a while.
INTO JAPANESE
どうしたの?私はしばらくあなたを見ていない。
BACK INTO ENGLISH
What's wrong? I have not seen you for a while.
INTO JAPANESE
どうしましたか?私はしばらくあなたを見ていない。
BACK INTO ENGLISH
What's wrong? I have not seen you for a while.
That didn't even make that much sense in English.