Can you gain the benefits of weapons you're not proficient in?

[Jhe'Nefhar]

To elaborate: if you are holding a weapon which you are not proficient with, but are not attacking with it, can you still gain the non-damage related benefits of it? As a "purely hypothetical" example, if I'm playing a character wielding a broadblade shortsword (essentially a shortsword which grants an extra +2 to AC if you're fighting defensively, using total defense or shifting 2 or more points to AC via combat expertise), even if they're not proficient with it... could I still get the bonus to AC if I'm fighting defensively? I looked through the Player's Handbook, but it's never mentioned whether the special features apply to nonproficient weapons.

Thanks!

[Larkas]

Of course. Lack of proficiency merely gives you -4 to attack, and that's it.