4.5.1. Fourth Declension

1.  The Stem of nouns of the Fourth Declension ends in -e/o, i.e. they are thematic. They can be animates and inanimates, as well as adjectives. The inanimates have an ending -m only in Nom.-Acc.-Voc. The animates, with a Nominative -s, are generally masculine in nouns and adjectives, but there are also feminine nouns and animate adjectives in -os, as remains of the old indistinctness of declension.

2. The e/o stems are declined:

 

Animate

Inanimate

NOM.

-os

                                -om

ACC.

-om

VOC.

-e

GEN.

-os, -osio, -oso, -i

OBL.

-oi, -oi, -ei;  -o, -e

NOTE. It is obvious that this model could have been written without the initial vowel -o-, given that the probable origin of this vowel is the theme vowel of some thematic stems, while other, primitive athematic stems were reinterpreted thereafter and this vowel was added to them by way of analogy. So, for thematic stems, like wlqo-, this system should be read Nom. -s, Acc. -m, Voc. -e, Gen. -s, -sio, -so, -i.

3. There is obviously a possible confusion between the Nominative and the Genitive in -os. This can only be solved with lengthenings, as in -os-io or os-o.