if

[Will Txankamuse]

txo = if

Txo new nga rivey, oehu! [source]
Come with me if you want to live.

This satisfies #1 from the wiktionary definition

It would be nice to know if we can use txo in other sentences (such as this one!) i.e. as meaning 'whether'. (#5 from the definition page)

Do you know if Na'vi eat meat?

Will

[Hawnuyu atxen]

Although i'm not sure, i think we can (theese are synonyms as i know/see...)
... but since i'm no linguist i can be wrong (and i'm tired too...)

[wm.annis]

Although i'm not sure, i think we can (theese are synonyms as i know/see...)

I would be very, very careful of this.  The question to ask Frommer is, how do we ask an indirect yes/no question.  Indirect statements get a direct quote, so I would take care with indirect yes-no questions.  Using if-words for that is by no means universal.

[Hawnuyu atxen]

Ah... i said that it's late (rather early...) here...
Definitely, for the yes/no questions it's better to just use srak...

[Will Txankamuse]

The other use of 'if' doesn't always have to be a question.

I'll know if you're lying or not.

Still don't think that's txo but I might be wrong...

Will