Old Irish - Orthography

Orthography

As with most medieval languages, the orthography of Old Irish is not fixed, so the following statements are to be taken as generalizations only. Individual manuscripts may vary greatly from these guidelines.

The Old Irish alphabet consists of the following eighteen letters of the Latin alphabet:

a, b, c, d, e, f, g, h, i, l, m, n, o, p, r, s, t, u

In addition, the acute accent and the superdot are used as diacritics with certain letters:

• The acute accent indicates a long vowel. The following are long vowels: á, é, í, ó, ú.
• The superdot indicates the lenition of f and s: ḟ is silent, ṡ is pronounced /h/
• The superdot is also sometimes used on m and n with no change in pronunciation, when these letters are used to mark the nasalization mutation: ṁ, ṅ.

A number of digraphs are also used:

The letter i is placed after a vowel letter to indicate that the following consonant was slender: ai, ei, oi, ui; ái, éi, ói, úi

The letter h is placed after c, t, p to indicate a fricative: ch, th, ph

The diphthongs are also indicated by digraphs: áe/aí, ía, uí, áu, óe/oí, úa, éu, óu, iu, au, eu

In word-initial position, when no initial consonant mutation has applied, the consonant letters have the following values; they are broad before back vowels (a, o, u) and slender before front vowels (e, i):

Although Old Irish has both a sound /h/ and a letter h, there is no consistent relationship between the two. Vowel-initial words are sometimes written with an unpronounced h, especially if they are very short (the preposition i "in" was sometimes written hi) or if they need to be emphasized (the name of Ireland, Ériu, was sometimes written Hériu). On the other hand, words that begin with the sound /h/ are usually written without it, for example a ór /a hoːr/ "her gold". If the sound and the spelling cooccur, it is by coincidence, as ní hed /Nʲiː heð/ "it is not".

After a vowel or l, n, or r the letters c, p, t can stand for either voiced or voiceless stops; they can also be written double with either value:

After a vowel the letters b, d, g stand for the fricatives /v, ð, ɣ/ or their slender equivalents:

After m, b is a stop, but after d, l and r it is a fricative:

After n and r, d is a stop

After n, l, and r, g is usually a stop, but it is a fricative in a few words:

After vowels m is usually a fricative, but sometimes a (nasal) stop, in which case it is also often written double:

The digraphs ch, ph, th do not occur in word-initial position except under lenition, but wherever they occur they are pronounced /x/, /f/, /θ/.

The letters l, n, and r are written double when they indicate the tense sonorants, single when they indicate the lax sonorants. (But the tense sonorants are usually written single in word-initial position.)