Definitionen
1.AdverbAt what time? At which time? Upon which occasion or circumstance? Used to introduce direct or indirect questions about time."When will they arrive?; Do you know when they arrived?; I don't know when they arrived.; When they arrived is unknown.; The site's all bugged. Fix when?; Tank class buff when?; My fridge even restocks itself these days. Glorious AI overlords when?"
2.AdverbUsed after a noun or noun phrase in isolation to express impatience with an anticipated future event."The site's all bugged. Fix when?; Tank class buff when?; My fridge even restocks itself these days. Glorious AI overlords when?"
3.AdverbAt an earlier time and under different, usually less favorable, circumstances."He's mister high and mighty now, but I remember him when."
4.AdverbAt which, on which, during which: often omitted or replaced with that."That was the day when the Twin Towers fell.; Not a week goes by when I don't mourn that loss."
5.AdverbThe time at, on or during which."I recall when they were called the Greys.; Next year is when we elect a new mayor."
6.AdverbA circumstance or situation in which."Love is when you can't get enough of someone."
7.ConjunctionAt (or as soon as) that time that; at the (or any and every) time that; if."Pavlov's dogs salivate when [i.e. at any and every time that] they hear a bell.; When [i.e. at any and every time that] he speaks to her, he is always polite.; Put your pencil down when [i.e. as soon as, at the moment that] the timer goes off.; A player wins when [as soon as, or at any time that, if] she has four cards of the same suit.; A student is disqualified when [as soon as, if] they cheat.; Don't forget to signal when (you are) turning right.; When she'd written her letters, she did some gardening.; Jose, when he finally managed to go to sleep, had a series of bad dreams."
8.ConjunctionDuring the time that; at the time of the action of the following clause or participle phrase."They dream when [i.e. during the time that] they sleep.; I'm happiest when [during the time that, or at any time that] I’m working.; It was raining when I came yesterday.; The game is over when the referee says it is.; Be careful when crossing the street.; When (you are) angry, count to ten before speaking or acting."
9.ConjunctionAt what time; at which time."I am here till Friday, when [i.e. at which time] I leave for Senegal.; I was just walking down the street, when [i.e. at which time] all of a sudden it started to rain."
10.ConjunctionSince; given the fact that; considering that."I don't see the point of putting up Christmas decorations when I am the only person who is going to see them."
11.ConjunctionWhereas; although; at the same time as; in spite of the fact that."You're picking at your scabs when you should be letting them heal.; He keeps changing things when the existing system works perfectly well."
12.PronounWhat time; which time."Since when do I need your permission?"
13.NounThe time at which something happens."A good article will cover the who, the what, the when, the where, the why and the how."
14.InterjectionThat's enough: a command asking someone to stop adding something, especially an ingredient or portion of food or drink; used in, or as if in, literal response to 'Say when'.
15.InterjectionExpressing impatience.