However, other pieces may be dropped to give immediate checkmate, a pawn that is already on the board may be advanced to give checkmate, and a pawn may be dropped so that either it or another piece can give checkmate on a subsequent turn.
However, other pieces may be dropped to give immediate checkmate, a pawn may be advanced to give checkmate. This pawn is already on the board. A pawn may be dropped. Either it can give checkmate on a subsequent turn. Either another piece can give checkmate on a subsequent turn.