Poswa nouns
Poswa preserves the six noun cases of the parent language with almost no changes in meaning or form, apart from regular sound changes. The possessive has weakened into a genitive when used with definite nouns, however. e.g. teppiopwas mupawabub "the length of the rope". Poswa has not added any new cases; so there is still no dative case and the various uses of the locative case are not distinguished.
- Nominative: The default form of the word, used as the subject of a sentence and also in genitive phrases when not indicating possession; paslam "fire"; paslam boša "fire hearth; fireplace".
- Accusative: Always marked by -p, shows the object of a verb. Žazba pasliap blabwambi "The girl put out the fire".
Number
There is no "grammatical" plural in Poswa in the sense that there is not a separate table of forms for plural nouns in each declension. To pluralize a noun, either -by or -bum is added. The difference between the two is that -by implies separation amongst the individual items being described, whereas -bum implies that they are working together. An animate noun can take either of the two suffixes depending on which meaning is intended; inanimate nouns have a fixed plural form, however, in a manner similar to the way nouns have genders in Spanish and some IE languages. Note that body parts, and inalienable nouns in general, inherit their animacy from an implicit "parent noun", and therefore are understood as animate nouns in any context, even if the person whose body they belong to is a corpse or a doll.
Possession
Possession markers can be placed on any noun, e.g. papwopwa "dog"; papwopio "my dog"; poppup "knife" ---> poppuwio "my knife". The stem to which the possession marker attaches is called a soppu.