The document discusses the Indonesian language prefix "per-". It has three forms: per-, pe-, and pel-. Per- is used with words not starting with r, pe- with words starting with r, and pel- is only used in the word "pelajar". The prefix per- forms command verbs and can be used in command sentences, sentences with an aspect + actor + verb structure, and additional information on subjects/objects with yang + aspect + actor + verb. The prefix per- can provide meanings of "make over", "regarded as", or "divide" depending on the base word it is added to.