Is it possible to foul another player without touching him?

Answer 1

A "foul" commonly refers to the ten offenses for which a direct free kick or a penalty kick is awarded (called "penal fouls"), but technically includes the eight indirect free kick offenses as well. The latter group (IFK offenses) generally do not require there to be contact between players. Some of the penal fouls occur upon the making of inappropriate contact with an opponent, while others only require that the illegal contact be attempted. The first penal foul listed in the Laws of the Game is "kicks or attempts to kick an opponent"; contact is not necessary if the referee believes that the offender attempted to kick the opponent, but missed (in this case, the referee should consider that misconduct may also have to be sanctioned).

Answer 2

The term "foul" is not well-enough defined to answer this question. There are free kick offenses that require touching and others that don't.