please correct

['itan ayvrrtepyä]

ok im going to try to write a sentence in navi

Oe ke omum txo ayfi'u aylì'u ngay lu.

[Hawnuyu atxen]

Kaltxì!

I'm not sure about the useage of "txo" (if it can be used like this)... but i think it's okay...
I think you should use "fay-" on "lì'u", rather than using both "ayfì'u" and "aylì'u".

Other than that it's ok.

['itan ayvrrtepyä]

ive never seen the prefix fay- what does it do?

[Rangtsulfätu]

Fay+ is a contraction of fi'u and ay, so it means "these". Same as you were trying to do with ayfi'u.

['itan ayvrrtepyä]

ok cool irayo