You can use melee weapons two size category larger than you are with a -4 penalty on the attack roll, but the amount of effort it takes you to use the weapon does not change. For instance, a Huge longsword (a one-handed weapon for a Huge creature) is considered impossible for a Medium creature to wield. For a Medium creature that has this feat, it is still considered a one-handed weapon. You can wield a larger light weapon as a light weapon, or a larger two-handed weapon in two hands. You cannot wield a larger weapon in your off hand, and you cannot use this feat with a double weapon.
While you are wielding a weapon that is two size category larger than you are, you calculate your reach as if you are one size category larger.
You can use a melee weapon one size category larger than you are with a -2 penalty on the attack roll, and the amount of effort it takes to use the weapon increases. A larger light weapon is considered a one-handed weapon, a larger one-handed weapon is considered a two-handed weapon, and you cannot use a larger two-handed weapon at all.
