A feat sometimes requires you to have a certain ability
score, which is the case with Two-Weapon Fighting (it
requires Dex 15). A character has, say, Dex 13, but wears
an item, in this case gloves of Dexterity +2, and now her Dex
score is 15. Can she take the feat and have it be active only
when she wears the item?
Actually yes, she could take the feat, but she would lose the
use of the feat if, for whatever reason, she loses the bonus from
the item.
Problem Solved.