It is a linguistic work dealing with Old Norse, in the tradition of Latin and Greek grammatical treatises, generally dated to the mid-12th century.
[3] It is also notable for revealing the existence of a whole series of nasal vowel phonemes, whose presence in the Icelandic language of the time would otherwise be unknown.
The Treatise is important for the study of Old Norse, as it is a major text showing the state of the language just prior to the writing of the Icelandic Sagas.
This alphabet included þ (derived straight from the runes), as well as diacritic indication of vowel length, and an o with an ogonek.
The First Grammarian's entire system was never adopted, as evidenced in later manuscripts,[4] in some cases not much younger, but it has had an influence on Icelandic writing ever since (see above).
[5] Vowels (Raddarstafir, "reard (sound) staves"): a, ȧ, ǫ, ǫ̇, e, ė, ę, ę̇, ı, i, o, ȯ, ø, ø̇, u, u̇, y, ẏ Consonants (Samhljóðendr, "co-sound (consonance) ends"): b, ʙ, c, ᴋ, d, ᴅ, f, ꜰ, g, ɢ, ꞡ, h, l, ʟ, m, ᴍ, n, ɴ, p, ᴘ, r, ʀ, ſ, ꜱ, t, ᴛ, þ Samsettar (Letters for composite sounds): x, z Other: ⁊, ˜ Based on the description of minimal pairs of words in Old Norse, Einar Haugen proposes one tentative interpretation of the vowel description given by the First Grammatical Treatise.
This can be seen in the illustrative sentences used in demonstrating minimal pairs, which contain allusions to "the giantess Þórgerð Hǫlgabrúð (90.20), Thor and the giant Hymir (90.20), and the legendary Dane Ubbi (90.19)".