1.used for asking at what time something happens; used for asking in what kind of situation something happens; used when someone knows or says at what time something happens, or in what situation it happens
2.as soon as another action or event has finished; at the same time as something else; at a point during the time that something else is happening
3.used for talking about a particular time or situation
4.used for introducing a situation that makes someone’s action or behavior seem surprising
5.used for making a general statement about something that is always true or correct
whens