Client language "half-changed"

Hey there!
I recently started on this server, brinfing some friends. I don't have such an hard time with the english client, but I'm trying to change the client's language so my friends can also fully enjoy their stay here.
I managed to change the client locale, so now all my interface, voiceovers, and whatsoever are converted in my native language (italian). The only things that's still in english are all the dialogue boxes for quests, short dialogues, and every other "plot-related" text in the game... which is a good portion of the fun, since we enjoy the roleplaying experience of this game.

Any help, please?

Those texts are coming from the server. The expansion you are playing on probably doesn't support other languages on server side.

I see... I'll deal with it then.

Correct. Client Language change only really affects what you noticed, Quest texts and alike come from the server and if server doesn't have them on your language it will send default.

So I'm supposing there isn't a ... manual workaround to this

No, there is not, one ingame that is. You can go on http://it.wowhead.com/ for example and read there.

Oh, I didn't think about it, thanks!