Verb:GRIP

The Grip verb allows a character to switch weapons such as the katana, bastard sword, javelin, trident or spear between one-handed and two-handed use. It also displays the following message:

You grip your <item> a little tighter.

Where the item is any item in your right hand.

Usage:
    GRIP [STATUS]             - If holding a switchable weapon, displays current grip status
    GRIP {switchable weapon}  - Switches current grip between one-handed and two-handed
    GRIP [other object]       - If holding an object other than a switchable weapon, tighten your grip on an object
    GRIP ONE                  - Switches weapon in right hand to one-handed grip
    GRIP TWO                  - Switches weapon in right hand to two-handed grip

You must have your left hand free to switch a weapon into two-handed grip. Grip can enable certain attacks like trip, which can only work with a two-handed polearm.