Every character gains a Native Language at first level (unless they take the Born of Two Peoples feat, in which case they may take up to two Native Languages, depending on which Cultures they select). The character speaks their Native Language(s) at the “Native-Speaker” level of proficiency, and all other languages at the “Untrained” level. For every rank invested in Linguistics, a character can increase their proficiency in any language by one fluency-level.
Speaking or understanding a language in which you are less than "Fluent" requires you to make a roll: d20 + your Linguistics modifier + either your Wisdom modifier (if you are trying to understand someone else) or Charisma modifier (if trying to make someone else understand you). Roll each only once per conversation. If you fail, you cannot try to communicate with that specific individual in this language until you have gained a level. (Thus, it is possible, if you succeed in one roll but fail the other, to hold a conversation where you can understand the other speaker but they cannot understand you, or vice-versa.)
The difficulty of the roll depends on creature type and how closely the individual's language is related to any of your own languages. It is easiest to communicate with those who speak languages which are related to your own. In this case, if the individual's language is a member of the same language family as any language you know, the DC is 10. If the individual does not know any of these languages, the DC is 20. (See Linguistics, Pathfinder Player's Handbook, pg. ??). The DM may choose to ignore this check at his/her discretion, in the interest of keeping things moving and to satisfy the demands of the plot.
The above DCs increase by 5 if the speaker is a fey, giant, or monstrous humanoid; they increase by 10 if the speaker is an elemental. If the other individual is of any other creature type, communication via spoken or written language becomes impossible (though abilities and spells like Telepathy and Comprehend Languages can overcome this obstacle).
If the speaker is deliberately trying to make themselves understood, you gain a +2 circumstance bonus on this roll. If you are attempting to interpret their speech from outside normal conversational distance (such as eavesdropping), you take a -4 penalty on this roll. It is possible to take 10 on a Linguistics check, but only if the listener is willing to wait several minutes for the speaker to get their point across.
Untrained (0 ranks) You haven’t the foggiest notion of how to communicate with speakers of this language. You can sometimes pick out the names of people and places you’re familiar with, and you can use pantomime to signify certain actions, but anything beyond the simplest statements is impossible for you to discern or express clearly.
- You take a -15 penalty on Linguistics checks to communicate with speakers of this language.
- Understanding or communicating anything more complex than a one- or two-word sentence automatically results in failure.
- If you miss the DC by more than 15, the result is treated as a critical failure.
Novice (1 rank) You can ask for food and shelter, take and give directions, and complete most simple transactions without forgetting your courtesies and honorifics, but unchaperoned immersion in this language is often confusing to you, and can be frightening if any serious misunderstanding arises.
- You take a -10 penalty on Linguistics checks to communicate with speakers of this language.
- If you miss the DC by more than 10, the result is treated as a critical failure.
Intermediate (2 ranks) You know basic vocabulary words (time and date, cardinal directions, family and relationships, weather, etc.) and phrases (greetings, farewells, titles, etc.), but your sentences are clumsy. You restructure your sentences awkwardly, to avoid exposing your ignorance of certain words and grammatical rules. You speak this language well enough to hold a simple occupation, such as a manual laborer or animal-herder.
- You take a -5 penalty on Linguistics checks to communicate with speakers of this language.
Conversational (3 ranks) You can usually carry an entire conversation with a native speaker, making only the occasional grammatical mistake or using the wrong word. You are able to discuss some abstract concepts, and rarely need to ask others to speak more slowly or repeat themselves. You speak this language well enough to hold a more complex occupation, such as serving drinks in a tavern or making deliveries.
- You take a -2 penalty on Linguistics checks to communicate with speakers of this language.
Fluent (4 ranks) You can speak this language almost as well as someone who learned it from birth. Your linguistic skills would not prevent you from holding any professional occupation.
- You take no penalty on Linguistics checks to communicate with other speakers of this language, though it’s still possible for native-speakers to make their speech incomprehensible to you through euphemisms, wordplay, and slang.
Native-Speaker (5 ranks) This language is your mother-tongue. You speak it as easily as breathing or walking. •You do not have to make Linguistics checks to communicate with others who speak this language. •You gain a +2 competence bonus on Diplomacy checks against those who have this language as their culture's Native Language. •This level of proficiency can only be attained by characters who possess a Culture which has this language as its Native Language.
The ability to read and write is entirely separate from linguistic skill with a given language. Instead it is represented by a series of feats: