hrmm. comments like this make me worry.
Orcs are elves. They are known as Orsimer, note the 'mer' at the end of that. Mer means 'elf' which is why you see it in Dunmer, Altmer, Falmer and Bosmer, all the elven races. It is not a coincidence, Orcs are elves.
It seems you weren't actually worried by the claim that Orcs are Elves, rather that somebody hadn't known about Orcish. This makes my post rather irrelevant. Oh well I guess its just a fun fact now.