Puckish: I would not think it would be acceptable. Only after the move is made, then going back and asking "Did I do this correct, or would you have done something different" would be the most acceptable thing.
That way they are still playing their own game, plus learning how to play better the next time is a similar situation comes up.
(hide) If you are waiting for your turn, click on "change" next to the "refresh" on the main page, then set refresh the page to 30 seconds to get your turn to move displayed faster. (Servant) (show all tips)