Can this also mean "You phone" (i.e. make a phone call to someone)?
I believe "phone" is a transitive verb in English, so your English sentence doesn't really have sense (?).
"phone somebody" = "telefonál valakinek" (dative case) or "felhív valakit" (accusative case)
It did not accept "are you telephoning"
We do say things like "phone the office" or "call your aunt."
All that in one word. Unbelievable.
Accepted: "you are on the phone" which is common usage.
I typed what I heard, which was "telefonász". This shouldn't have been accepted as the correct answer seems to be "telefonálsz".
I can not hear the sz sound at the end of the word 'telefonal '. I have reported it.
Sounds good to me :|