a long time ago, in a 2ed campaign far away.....
We used to use this weird system for doing languages, it was fun and involved a lot of roleplaying.
Lets say you know a language, but are not a native speaker, until you get a lot of proficiency (i.e. skill ranks) you can only use certain words with certain vowels.
For example, lets say i have orcish at rank 1, we would have you get to use only words with the vowels "A and I" or something like that. If it contained any other vowels, you could not understand it or say it. So you replace those words with made up words (if you are the DM) and it sounds really cool, to understand bits and pieces of the conversation, and try to piece it together, its a lot of fun and makes great roleplaying if you get it right.
An example orcish threat to a person who has a limited understanding of orcish:
The threat is "You soft skins will die now!!"
vowels "A" and "I" only @ Rank 1 sounds like "KRoog Dugla skins will Dertoosh kurg!"
then it could progress to more vowels every 2 ranks or so, so you could understand words with the vowel "O" in them, so the phrase then sounds like :
"Kroog soft skins will dertoosh now!"
and so on and so forth, adding vowels until you get it all, trust me, its fun if you can get used to it. I hope that wasnt too confusing
