indicates controlling possession of a thing, used either as a suffix, prefix, or affix
uikai na ye: my book, book of me (emphasizes book)
ye na uikai: my book, book of me (emphasizes owner of book, me)
introduces a relative clause expressing activity on the part of the topic preceding the relative clause
ar na vail najail: the person who is talking is knowing [of what s/he is talking about] (could also be expressed ar, ar ha vail: "person, person the talking")
ar na dosil ea rajil: the person who is murdering is being arrested.
Usage notes
The particle na indicates real ownership, that is, having rights over an object or thing (as a book, movie, play) such as creator's rights, as opposed to mere possession. It suggests actual control of that thing rather than just having it. Therefore, uikai na ye indicates that the book is written by me rather than bought for reading purposes. The reason that the possessed and the possessor can switch positions in a phrase is that the noun of more animacy is always considered the possessor.