Definition of "when" in Englisch

adverb

1. (interrogative) At 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.

2. At an earlier time and under different, usually less favorable, circumstances.

   • He's mister high and mighty now, but I remember him when.

3. (relative) At 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.

4. (fused relative) The time at, on or during which.

   • I recall when they were called the Greys.
   • Next year is when we elect a new mayor.

5. (informal, in definitions or explanations) A circumstance or situation in which.

   • Love is when you can't get enough of someone.

conjunction

1. At (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.

2. During 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.

3. At what time; at which time.

   • I am here till Friday, when [i.e. at which time] I leave for Senegal.