�Hola!
There is a nice site, in fact it is an online dictionary, that I find very useful. It is
WebReference.
There, I typed "vez" and I got, among other uses, the ones related with "de una vez":
-
de una vez, (sin interrupci�n) in one go (expresando impaciencia) �terminemos de una vez!, let's have done with it!
-
de una vez por todas / de una vez para siempre , once and for all
I'll give you some examples:
With "de una vez"
He bebido toda la leche de una vez.
and
�Quiero que termines esto de una vez por todas!
Do you (or anybody) want to try and translate these 2 sentences?? :-)
(In case you find it too difficult, let me know and I'll tell you, ok?
Hope this helps,
