Demonstratives act like determiners, attaching to classifiers, pronouns or pronimal clitics, though they can co-occur with determiners, in which case they come first: [dem]=[det]=[cls]. They have both familiarity and deictic meanings and overtones of temporal meaning.
da | this, familiar to speaker | here | now |
su | that, neutral familiarity to speaker, familiar to hearer | there | then |
yo | that yon, that other, unfamiliar to speaker or hearer | yonder | then (future) |