As in many North American languages, verbs constitute complete clauses in themselves.

Nominals may accompany the verbs, but they have adjunct status, functioning as appositives to the pronominal affixes.

When the reflexive follows can ergative–absolutive pronoun sequence, it indicates that one indirectly affected is the same as the ergative.

When it follows an absolutive–dative pronoun sequence, it indicates that one indirectly affected is associated with the absolutive, perhaps as the whole in a part-whole relationship, or the owner.

The possessive prefix for the third person singular is -ga- when the noun itself is feminine, neuter, dual, or plural.

It is preceded by the gender-number prefixes: The possessive prefix for the first person singular ("my") is –gE (Wishram -g-, -k-; -x̩- before k-stops) when the noun is feminine, neuter, dual or plural, but -tcE-, -tci- (Wishram -tc-) when the noun is masculine.

Chinook-speaking groups were once powerful in trade, before and during early European contact (Lewis & Clark), hence developed the Chinook Jargon – a pre-European contact language, with lexicon from at least Chinook, Chehalis, and Nootka or Nuu-chah-nulth.

Chinook people were quickly diminished by European diseases: Numbered around 800 persons in 1800; they mixed with Chehalis (in fact, the very word Chinook is a Chehalis word for those who lived on the south of the river).

Chinook Jargon also flourished from 1790s–1830s, then experienced a flood of English and French new vocabulary.

in Jan. 2001, but in the 90-day grace period the Quinault Tribe filed an appeal stating that the Chinook Nation made mistakes when applying for federal recognition.