It should be added as an option, as it is technically correct, however it is not commonly used
Not really and both can be used by themselves. You can even pair them together. "Tôi chờ đợi bạn lâu lắm rồi" = I've been waiting for you for a long time now.
Thank you so much for the quick response ^^~
So, is It correct if change chò into đợi ?
Bạn đang chò ai = bạn đang đợi ai ?
Both are correct and you can even ask "bạn đang chờ đợi ai?"
NOTE: It's chờ not chò.
or, to be perfectly correct, "For whom are you waiting?" But in real life, everyone just says it like that. ("Who are you waiting for?") The "rule" is that you cannot end a sentence with a preposition. However, in spoken English, everyone does!