All characters know how to speak Common. A dwarf, elf, gnome, half-elf, half-orc, or halfling also speaks a racial language, as appropriate. A character who has an Intelligence bonus at 1st level speaks other languages as well, one extra language per point of Intelligence bonus as a starting character.
Literacy: Any character except a barbarian can read and write all the languages he or she speaks.
Class-Related Languages: Clerics, druids, and wizards can choose certain languages as bonus languages even if they're not on the lists found in the race descriptions. These class-related languages are as follows:
Cleric: Abyssal, Celestial, Infernal.
Druid: Sylvan.
Wizard: Draconic.