mu
The derivational marker mu turns the following word into a noun that is the agent (doer) of that verb. It can be compared to the "-er" suffix in English.
mu makan - "entity that eats", "eater"
It is not specified exactly what is doing the action. In the above example, it could refer to a person, an animal, or whatever else. mu is often used along with sensory verbs such as teka, sema and anan to talk about sensory organs (eyes, ears and nose, respectively):
mu teka - "entity that sees", "eyes"
If you want to specify what the agent is, you can put a word before it:
nin mu teka - "person who sees"
conto mu teka - "machine that sees"
osa salila mu teka - "part of the body that sees", "eyes"
Using je, you can indicate the object of the verb:
mu makan je sito - "eater of bread", "bread eater"
It also works with base modifiers and base nouns (intransitive verbs):
mu lo - "thing that is moving", "one who moves", "mover", "traveler", etc.
mu sito - "thing that is bread"
nin mu namuna - "person that is an example"
Difference from "te"
As described above, mu allows you to not specify the subject of the verb, unlike te, which requires a preceding noun, else it becomes an infinitive verb:
The infinitive verbs refer to the general ocurrence of an action. For example, te konkulen refers to the act of competing, not a specific competition. The construction "tun mu" can be used to indicate a singular action:
te konkulen, le tope - "competing is good"
tun mu konkulen le tope - "the competition is good" (literally, "the action that competes is good" or "the action of competitors is good")
Additionally, mu carries a connotation of task or role. I can be a:
nin te kuwekan - "person that is farming"
without being a