Wiktionary:About Primitive Irish

Defining the language
Primitive Irish (ISO 639-3 code pgl) is defined here as Goidelic terms dating to the 6th century or before and written in Ogham. Later terms may be considered Old Irish, Middle Irish, Modern Irish or Scottish Gaelic. Please also note that not all inscriptions in Ogham are necessarily in Primitive Irish.

All terms should have an entry with a title in Ogham, and another entry with the transliteration as its title and the following content:

Romanization


where  is replaced by the title of the main entry for that word in Ogham.

If a Primitive Irish word has descendants in Old Irish, modern Irish, Scottish Gaelic, or Manx, these may be listed in a "Descendants" section.

For nouns, the lemma form is the genitive singular (for most nouns, this is the only attested form).

Sound changes
NOTES 1 Imported from Latin.

Declension
There are several types of declensions for masculine nouns and one (known) declension for feminine nouns.

MASCULINE

FEMININE NOTES 1 This later developed into o or u. 2 This later developed into tas.

Example of development
PROTO-CELTIC wiros PRIMITIVE IRISH viras (os > as) veras (i lowers to match the a) verah (s becomes h) vera (s dropped) ver (apocope finalised) OLD IRISH fer

PROTO-CELTIC rorīgos /roriːgos/ PRIMITIVE IRISH rurīgos (i affection) /ruriːɣos/ ruregas (o affection + os > as) /rureɣas/ ruregah (s becomes h) /rureɣah/ rurega (s dropped) /rureɣa/ rureg (apocope finalised) /rureɣ/ OLD IRISH ruirech /rurʲex/