adv., conj., pron., & n.
--interrog.adv.
1. at what time? 2 on what occasion? 3 how soon? 4 how long ago?
--rel.adv. (prec. by time etc.) at or on which (there are times when I could cry).
--conj.
1. at the or any time that; as soon as (come when you like; come when ready; when I was your age).
2 although; considering that (why stand up when you could sit down?).
3 after which; and then; but just then (was nearly asleep when the bell rang).
--pron. what time? (till when can you stay?; since when it has been better).
--n. time, occasion, date (fixed the where and when).
Etymology: OE hwanne, hwenne