Do you hang up a cellphone?

Yes, it does. "Disconnect the call" is also possible (although more technical).

Yes, you do. You can disconnect or hang up.

Even though we do not literally hang up the phone anymore, hang up has become idiomatic fro "disconnect the telephone connection".

This is not something new from the age of the mobile phone, even with a lot of "home phones" you have not been "hanging up" in the literal sense for a very long time.

On old telephones, you had to hang the "handset", rather the speaker part, back on a hook on the telephone. That hook would act as a switch to disconnect.

Compare it to to dial a number: we have not been dialling numbers in the literal sense for ages, the expression stems from the days when telephones had a dial that you would have to turn to form the number.

When we started effectively typing the number, we still called it dialling.

Although I'd avoid hanging up a mobile phone, and would rather ring off, the usage is widespread. Most mobile phones have pictograms showing telephone handsets on buttons that you press to start or end a call, justifying, in some way, the metaphorical shift. There's a reference to hanging up in the contxt of mobile telephone calls in Debrett here.

I also prefer to use 'ring' rather than dial, or for example, if my wife's got a friend's number on her mobile that I haven't got on mine, I'd probably say, 'Woukd you connect me to ...' Or 'would you ring ...'.

In Britain I don't remember ever using 'hang-up'as regards the phone. Though I do recall one or two of the old phones still lurking around in the 1950s where you did actually hang-up the receiver.

The term we always used was 'ring-off', though Americans did continue to 'hang-up' even after the arrival of the compact phone with the receiver rest.

So I simply continue to 'ring-off' with my mobile, though I notice that some younger people say 'end the call'.

Yes, one can.

Of course, it is applying a term that no longer has the direct meaning that it once did, but then teamsters no longer control a team of horses, core-dumps no longer have anything to do with ferrite cores, salaries are no longer paid in salt, and most people don't look at the stars when they consider something.

As such, it is one of a great many terms that relate to an historical artefact that is no longer relevant to the modern use.

For that matter, we still call them phones, when most that you can buy today are not actually phones, but rather multi-purpose pocket-sized computers that have a phone application among a great many others.

"ring off" is far older usage than "hang up" because it refers to (as someone said), turning the dynamo crank to inform the human operator to disconnect your circuit. Just plain "hanging up" was more advanced, after automatic switching arrived that could disconnect the circuit when you hung the receiver on the hook. So, the British are much farther behind in their word usage than the US. British still say "toilet", which was a euphemism - the original word means "grooming", as in "eau d'toilet" (literally: toilet water, as all 7 year-olds know.) But in the US we have had a string of successive euphemisms for the toilet, races of people, being handicapped (originally meant a disadvantage placed on a better player in a game) and so on. Maybe there is something to be said for not changing, until it no longer makes sense. New technology could bring new words instead of straining the old ones to incredulity and creating questions like this one.

From a cellphone industry insider's perspective, the terms used in the ETSI GSM specifications to describe the states relating to an audio connection are "on hook" and "off hook". This simply echoes the concept of hanging but from the equipment's viewpoint.

For an example reference (from a quick search for a public example) see this old ETSI specification, see section 5.2.5 etc.

"5.2.5.1 Lift the hand-set "Off Hook" - Dial tone is presented."

Hang up, because "Did you hang up on me?," expressed with righteous indignation, is still a basic verbal weapon of emotionally overwrought adolescence.

Whatever you say, do not use "slammed the receiver down" when referring to ending a call in anger. With a cell phone it could be a very expensive gesture!