There is no such thing as Common in Halda, and as such most races begin play with only a single language, typically that of its race. See individual races for rules. any race may learn any other race’s language as a bonus from high int, however some languages have special rules. Players may not begin play knowing a secret language unless they meet the prerequisites, and must receive training to learn it in game.
Dynan: The language of Dyn.
Numalan: The language of Numala.
Farlender: The language of Farlend.
Elvish: Language of the Elves.
Dwarven: Language of the Dwarves
Giant: Language of Giants and Ogres
Gnomish: Language of the Gnomes, and to some degree Halflings.
Goblin: Language of the Goblins.
Orcish: Language of the Orcs.
Low Draconic: Language of Kobolds and most Saurans. A simplified and highly regional form of Draconic.
Draconic: Common tongue used by Dragons when communicating with mortals. Typically used in magical writings.
High Draconic: Dragon speech. Mortal races can not speak High Draconic, but they may learn to understand it. Has no written form. Requires Int or Wis 13 for a mortal to learn.
True Draconic: A secret Dragon language, consisting entirely of mental symbols. Most mortals do not even realize this language exists, and only the oldest and most powerful of Dragons can use it.
Sylvan: Language of the Fey. Considered a secret language except to Elves, Gnomes, and those who begin play as druids.
High Dwarven: The oldest form of Dwarven, used in Dwarven holy writings. Considered secret except to Dwarves.
Shadow speak: A series of code phrases and symbols used by the Shadows, a guild of thieves and assassins. Considered secret unless you are a member, which requires a trait.
Kadari: An ancient necromantic language. Many forbidden spells and rituals are written in Kadari to hide their nature from casual readers. Considered secret except to those who begin play as necromancers, or with the death domain.
Others: Most outsider languages may be learned as well, but they are considered secret to anyone who does not posses some degree of appropriate magic, or ranks in Knowledge: Arcana or Knowledge: Religion.