Pronunciation: (kood; unstressed kud),[key] —v. a pt. of can1.
—auxiliary v. 1. (used to express possibility): I wonder who that could be at the door. That couldn't be true. 2. (used to express conditional possibility or ability): You could do it if you tried. 3. (used in making polite requests): Could you open the door for me, please? 4. (used in asking for permission): Could I borrow your pen? 5. (used in offering suggestions or advice): You could write and ask for more information. You could at least have called me.