Nouns in Wistra-Gutisk are inflected for case, number, and grammatical gender. There are three grammatical genders: masculine, feminine, neuter. For nouns with clear sexual gender, the grammatical gender generally agrees with the sexual gender. For example, qens 'woman' is feminine, so that natural gender and grammatical gender agree; but graba 'ditch' is also feminine, though the referent has no natural gender. There are two numbers: singular and plural (though personal pronouns and verbs also have a dual number). There are four cases: nominative (N), accusative (A), genitive (G), dative (D).

Case inflection is essentially a means of marking by suffixes grammatical functions which would otherwise be signalled by prepositions in Modern English. The most obvious remnant of the older case system in English is 's (apostrophe-s), which at the end of a noun fills the same role as the preposition of before a noun. For example, the bark of a dog is the same as a dog's bark. In much the same way, the nouns of Wistra-Gutisk use suffixes in order to denote grammatical function within a clause. Below is a short description of the case system.

Wistra-Gutisk declension is more robust than that of Modern English, though more sparse than that of Sanskrit. One may then envision the syntax associated with the case system in terms of the following question: how do the eight logical cases fit into the four extant cases of Wistra-Gutisk? The following chart gives the cases, along with the logical cases whose role each has subsumed.

The above identifications are not iron-clad, nor should they be taken for actual historical evolution. But they do go a long way to explaining the syntactic descriptions of WG case usage.

Like the other Germanic languages, WG has strong and weak nominal declensions. These are terms originally applied by J. Grimm to distinguish two types of declension within Germanic languages. Among nouns, the property of being strong or weak is inherent, each noun being either strong (only) or weak (only). Adjectives, by contrast, can be strong or weak depending on the situation: adjectives are declined strong when indefinite, weak when definite.