noun
definition
The time at which something happens.
example
A good article will cover the who, the what, the when, the where, the why and the how.
adverb
definition
(interrogative) At what time? At which time? Upon which occasion or circumstance? Used to introduce direct or indirect questions about time.
example
Do you know when they arrived?
definition
At an earlier time and under different, usually less favorable, circumstances.
example
He's mister high and mighty now, but I remember him when.
definition
(relative) At which, on which, during which: often omitted or replaced with that.
example
That was the day when the Twin Towers fell.
pronoun
definition
(interrogative) What time; which time.
example
Since when do I need your permission?
definition
The time that.
example
I recall when they were called the Greys.
conjunction
definition
At (or as soon as) that time that; at the (or any and every) time that; if.
example
A player wins when [as soon as, or at any time that, if] she has four cards of the same suit.
definition
During the time that; at the time of the action of the following clause or participle phrase.
example
Be careful when crossing the street.
definition
At what time; at which time.
example
I am here till Friday, when [i.e. at which time] I leave for Senegal.
definition
Since; given the fact that; considering that.
example
I don't see the point of putting up Christmas decorations when I am the only person who is going to see them.
definition
Whereas; although; at the same time as; in spite of the fact that.
example
He keeps changing things when the existing system works perfectly well.
interjection
definition
That's enough, a command to stop adding something, especially an ingredient of food or drink.
definition
Expressing impatience. (Compare what.)