To start using Gnome in game type -gn console command for Mith's Virtual Console.
Gnome is the language of all Gnomes, including Svirfneblin. They have no particular problem with others learning their language, generally, but each Gnome of Svirfneblin may have his or her own opinion on that.
Gnomes and Svirfneblins (Deep Gnomes) on Arelith both know Gnome, but it might not hurt to keep into consideration the difference in these two types of Gnome, namely that Gnomes and Deep Gnomes have since long been separated, and therefore their languages might not be fully transferable between the two races, much as is the case with the difference between the Drow version of Elven, Xanalress, and the surface Elven, where the comparison is made to American English and British English.
On Arelith this language is known by: