se

All sentences that make a statement require a verb in Kokanu. Although you can say things like "he nin maku", or "naki la", these sentences are not describing some sort of event, and are rather calls or reactions.

You could not say, for example, "I am at the house", without a verb being present in the sentence.

Therefore, the way to say "I am at the house" would be:
mi le se pi niwa

You could not just say "mi pi niwa", as this would just mean the sentence fragment "I, at the house". Without the verb marker le or o being used, the sentence does not have an action.

Remember that prepositions can be placed in any order. If you wanted to say "Me at the house", you'd have to say mi te pi niwa.

Saying "<noun> le se <preposition>" is quite a common structure, and is used for saying sentences such as:
ja le se nenka na sin. - "It exists because of that thing" mi le se kan ja. - "I am with him" na pawo le se sun Kanata. - "That dog is from Canada"

Due to how common this structure is, se is allowed to be dropped if it is between le and another preposition. So instead of needing to say:
mi le se pi na jan "I exist at that place"

You could say:
mi le pi na jan "I exist at that place" (exact same meaning)

This means that any structure that matches "le se <preposition>" can have its "se" dropped. (i.e. "le se <preposition>" -> "le <preposition>")