Proto-Finnic/Nominal cases

Ending
As with almost all languages with noun inflectional morphology, there is no ending in Proto-Finnic in singular. However, the nominative plural are formed by the suffix *-t to the oblique stem, and with most non-initial closed syllables are affected by consonant gradation (see /Phonology). Due to many phonological changes, the nominative singular form are often obscured from the oblique stem:
 * *kala "fish" → *kalat "fishes"
 * *joki "river" → *joget "rivers"
 * *veci "water" → *vedet "waters"
 * *pensas "brush" → *pensahet "brushes"
 * Proto-Uralic final *-e usually merges with *-i and thus coinciding with i-stem nominals in nominative singular.
 * The above change also caused assibilation of *-ti to *-ci.
 * However, *-e could also lost in words with more than three syllables. This change also further obscured the stem: *-me → *-n, *-kse → *-s.
 * The situation for the noun *südän "heart" is somewhat complicated due to later analogies, see /Nouns and adjectives.
 * Special case for the diminutive suffix *-inen: the oblique stem is always *-icet instead of expected *-inenet.

History
The nominative plural comes from Proto-Uralic *-t. However, in the plural suffixes for South Estonian and the rest of Southern Finnic are -q (pronounced with, e.g. kalaq) and -d (usually pronounced as written, except in Estonian, e.g. kalad).

Usage
Functions as subject of the sentence.

Ending
This case always coincides with Proto-Finnic genitive singular in the singular and nominative singular in the plural. It attaches to the oblique stem.
 * *kala "fish" → *kalan "fish (obj.)", *kalat "fishes (obj.)"
 * *joki → *joget
 * *veci "water" → *vedet "waters"
 * *pensas "brush" → *pensahet "brushes"

History
The accusative singular comes from Proto-Uralic *-m. Due to regular phonological changes, this case was morphologically indistinguishable from genitive singular (see more at Genitive section). The accusative plural is borrowed from Proto-Uralic *-t due to the previously-mentioned syncretism with genitive.

Usage
Functions as subject of the sentence.

Ending
It is marked by the suffix *-n, however, in the plural, it is either *-den or *-iden.
 * *kala "fish" → *kalan "fish (obj.)", *kalat "fishes (obj.)"
 * *joki → *joget
 * *veci "water" → *vedet "waters"
 * *pensas "brush" → *pensahet "brushes"

History
The accusative singular comes from Proto-Uralic *-m. Due to regular phonological changes, this case was morphologically indistinguishable from genitive singular (see more at Genitive section). The accusative plural is borrowed from Proto-Uralic *-t due to the previously-mentioned syncretism with genitive.