Sorry, I didn't realise it was a question...
El is a preverb that is not translatable in this case because it isn't there in its original meaning ("away") but has a sort of perfectioning function for the verb (here:
mond).
Mond (= tell) denotes just the action itself (it can be executed with/without anybody listening or with/without any particular topic or aim),
elmond is more specific: to tell about something to somebody, you have a listener there and a particular topic you want to communicate.
The preverb here is "cut off" from the verb and placed after it because of the sentence being a question and therefore changing the emphasis, etc. (So it does not change anything of the meaning explained above.)
