Let me say this, you are not a n00b the guy talking to you was a n00b, see Orcs can only speak in Orcish.
Same with Humans let me make this chart.
Horde.
Orcs- Orcish, default language of the Horde.
Trolls- Orcish and Troll, only Trolls can hear speak Trolls.
Tauren- Orcish and Taurahe, only Tauren can seak hear taurahe.
Undead- Orcish and Gutterspeak, Only Undead can speak and hear.
Blood Elfs. Orcish and whatever else language they have, Only blood Elves can hear it.
Alliance.
Humans- Common, Default language of the Alliance.
Dwarves- Common and Dwarven. Only Dwarves can hear it. You get the pattern?
Night Elfs- Whatever there language is called, Kaledori or something.
Gnomes- Gnomish.
New race? I dont know...
There you go. See you are not the noob, that guy was.
In fact your a newbie, I will not delve into the differnce.
Have fun...
Go ask in the Rogue Forum for help if you need Rogue help.
Alright? Have fun in WoW.