When
Definition of when:
part of speech: conjunction
At which time; at, or after, the time that; while: inter. At what time?.
part of speech: adverb
At what time? at which time: at or after the time that: while.
part of speech: adverb
At. or after, the time that; as, write when you can; at what time; as, when did it happen? as soon as; as, when the war is over.