There are many languages in WorldsTree, but communication is rarely a problem. The most often spoken Language is Common, which is a fusion of several Elven Languages and the Celene Language spoken in Silverymoon. It is a language all its own now, and well nigh ubiquitous, being many eons old.
Each of the Elf Tribes have their own language, as do each of the Wereclans have their own dialect. These are not incomprehensible to speakers of related languages and dialects, and learning is thus simplified.
Elves never invented an "ElfCommon" as Celenes did. Instead they rely on Old Elven, the universal language before the tribes split up. This serves to remind them of their heritage, and their differences.
LittlePeople, however, have devised their own version of Common, suited to their speaking and hearing range and rate. LittleSpeak would be fairly comprehensible if it were slowed down and pitched lower.
Birds also each have their own language. Dragons have a common tongue, and there is a special dialect spoken only by LungDragons.
There are several secret languages. The Glyph Harmonics are used to
encode Bardic music. Savants
use
a secret language call Cant. Thaumatergic is the language spoken when castings
spells using Lorecraft, and the language
used in their Tomes and Librams. Alchemists
use the Alchemical Lexicon, which is mostly code and jargon that cannot
be really spoken. Thieves use a thick slang language called Brogue and
Hse'eliae
can learn the language of Djinns.