esun - market, shop, fair, bazaar, business transaction
kiwen - hard object, metal, rock, stone
utala - battle, challenge, compete against, struggle against
nasin - way, custom, doctrine, method, path, road
anu - or
the particle anu isn't defined very well. lipu pu documents it barely, and many other courses gloss over really trying to explain anu.
i'm gonna do my best to give a good explanation
anu is a conjunction meaning "or", both inclusive and exclusive. it works a lot like how li and e work, but instead of defining a new part of speech, it defines an or to the current part of speech.
ona li jan
anu soweli
~ they're a person or a dog
waso li ken tawa lon ma
anu sewi
~ birds can move on the ground or in the sky
kasi anu suwi li ken moku
~ plants or sweets can be food
anu does not automatically mark a question, although it might also be used for questions. it's another area where it's poorly documented, so a lot of people do different things.
one way to use anu for questions might be to list the possible options, and then ask which option the listener agrees with.
waso anu soweli li ken. seme li pona mute tawa sina?
~ do you like birds or cats more?
(birds or cats are possible.
which do you like more?)