+lang
+language <new language>
Displays or selects your currently spoken language. This affects commands that say things in the room, such as say, pose, and to. It does not affect out-of-character commands such as page and +com. Setting a language may enhance or cripple your ability to talk with non-player characters as you meet them in the story.
When another player hears you speak a language they don't know 100%, your words are replaced by gibberish depending on how much they know that language. Knowing a language at least 10% allows you to somewhat read scrolls and write words. 50% is required to be able to speak in a tongue. At 90%, you can fluently speak the language and teach it to others.
Over time, you can learn the language that others are speaking by joining in a +party with them. They must have the language selected and in use during your travels. You will not know if you have learned the language until it reaches 10%. Some races initially start off with the ability to speak or understand more than one language.
From the winds.org Helptext - Courtesy Gandalf
-- SluggyQBFreak - 06 Feb 2005