Here's how I handle it:
Languages. Characters have separate ranks in each language, and characters can spend skill points to acquire ranks in languages.
1 rank implies ability sufficient to communicate with others who are taking time to speak slowly. If you are using the listen skill to try to determine the content of someone speaking in a language you only have 1 rank in, there is a circumstance penalty of -5.
2 ranks implies normal speaking fluency.
3 ranks implies literacy and improved fluency.
Additional ranks indicate exceptional fluency. 5 ranks in a language will give a +2 synergy bonus to skill checks using Diplomacy, Perform (Oratory), or Lawspeaking in that language.
Pidgin languages are limited to 2 ranks maximum.
Starting Languages
Every character starts with 2 ranks in their native language and, if they their native language is not Common, 1 rank in Common. Characters also get 1.5 skill points per Intelligence bonus (rounded up) to put in languages. PCs that start as clerics and wizards get an additional 2 ranks.
Clerics must have at least 3 ranks in a Clerical language and Wizards must have at least 3 ranks in whatever language they choose to write their spellbooks in, which may be [____]. If a cleric or wizard cannot gain these ranks from their starting language ranks, then they must spend ordinary skill points.