"A character of Medium or larger Size may use a 2-handed
weapon with one hand, but suffers a –4 penalty with his attack
check. Conversely, a character may hold a 1-handed weapon
with both hands, in which case his Strength score increases by 2
when determining damage."
Suppose I'm wielding a halberd in one hand at -4 and a claymore in the other at no penalty from Monkey Grip. Could I switch at will which one is penalized? As a GM I would rule that it's a Handle Item action.
I don't know why I'm asking since I don't think any player would ever do this, but hey I'm bored and I'm imagining a large unborn with six arms and six hurl battering rams.