Case is a grammatical category whose value reflects the grammatical function performed by a noun or pronoun in a phrase, clause, or sentence. In some languages, nouns, pronouns and their modifiers take different inflected forms depending on what case they are in.

Hilinqwo denotes case with the final letter:

~s Nominative (subject)
~m Accusative (direct object)
~t Vocative
Genitive/possessive
~n Indirect object, dative ("to")
~b Indirect object, ablative ("by/from")