User:Erisceres/Gaelic Etymological Orthography Project/Nominal Morphology

o-Stems

An identifiable characteristic of o-stems is that the stem-final consonant is broad in the nom. sg. form. A noticeable exception to this is the from día (and its proper noun form Día) which lost its stem-final consonant: nom. sg. (Old Irish) día < (Primitive Irish) díash < días < díìas < díìos. This stem-final consonant undergoes slenderisation in various paradigmatic forms. In the masc. o-stems, these forms include the nom. pl., voc. sg. and gen. sg., while in the neut. o-stems, only the gen. sg. undergoes slenderisation. A number of paradigmatic forms also have suffixes that follow the stem-final consonant. Masc. o-stems in the acc. and voc. pl. end with the -u suffix, while neut. o-stems in the nom. acc. and voc. long pl. end in the -a suffix. In the prep. du. and pl. of both masc. and neut. o-stems, a suffix is added that can be variably written as -ibh, -aibh or -oibh, depending on the qualities of the preceding phoneme.

The paradigmatic forms and their corresponding mutational affections are listed accordingly:

Masculine o-stems:

• No mutation: nom. sg.; prep. du. and pl.
• Lenition: nom. du. and pl.; acc. du.; voc. sg. and du.; gen. sg. and du.; prep. sg.
• Nasalisation: acc. sg.; gen. pl.
• h-prothesis: acc. pl.; voc. pl.;

Neuter o-stems:

• No mutation: prep. du. and pl.
• Lenition: nom. short pl.; acc. short pl.; voc. short pl.; gen. sg.; prep. sg.
• Nasalisation: nom. sg. and du.; acc. sg. and du.; voc. sg. and du.; gen. du. and pl.
• h-prothesis: nom. long. pl.; acc. long pl.; voc. long pl.

Besides these morphological qualities within the paradigm, o-stems can also undergo vowel alterations within their stems. If the stem is monosyllabic, since Old Irish predominantly puts its primary stress in the initial syllable, all vowel alterations occur on stressed vowels. If the stem is polysyllabic, alterations mostly occur in the unstressed stem-final syllable.