Which words can be one word sentences in tp?

[janMato]

I saw some discussion that mentioned the concept of "sentence words" which are words that are legal to stand alone as a single, complete sentence.

Which words in toki pona have this property?

[jan-ante]

interjections:
a
o
mu
pakala
pona
ike
and ala

[soweli Elepanto]

akesi,
toki...

[janSilipu]

Any content word can be a sentence as answer to a question. Probably most words can be sentences as observatives. Imperatives and the like require 'o'. Of course, this does depend on what you mean by "sentence", since none of the cases listed would be generated by the grammar floating about, which requires a subject and a verb.