2006In a conversation between two people about football, one person asks,
"Who was playing?".
The other person informs that this question is incorrrect as it is common knowledge that it takes two to play the game of football. It was identified that the first person could have asked:
"Which teams were playing?".
Though both questions are grammatically correct; was it improper to ask "Who was playing?"
I don't think so. The bottom line is that no one is going to ask "Which teams were playing?" when one can more simply ask "Who was playing?" (even though it is only one word shorter)
There is always an irresitable urge to shorten sentences, even if only by one word.
Finally, "Who was playing?" is a useful generic question that can refer to anything from a pickup flag-football game to professional sports to a musical or dramatic performance.
"Who (was)(is) playing?" is very firmly established in the English language.