The Irish Language Grimoire — The Irish Alphabet
The alphabet is the foundation. Before you can read an Irish word, conjugate a verb, translate a sentence, or recognise a name, you have to know the letters and how to say them. This page is the dedicated reference for the modern Irish alphabet. For the older carved-stroke script that preceded it, see the companion Ogham page.
The Irish alphabet is laid out here in four lessons: the eighteen letters, the síneadh fada, broad and slender consonants, and lenition. Click any letter on the grid below to see every Grimoire entry beginning with that letter, the Ogham tree-name associated with it, and a pronunciation note specific to that letter.
The eighteen letters
The traditional Irish alphabet has eighteen letters, in this order:
a b c d e f g h i l m n o p r s t u
Each letter has its own card below. Tap any card to open that letter’s full Grimoire page, where every word beginning with that letter is grouped by theme. The Ogham tree-name (ailm, beith, coll…) is the medieval Irish name for each letter, drawn from the alphabet of carved tree-letters used on inscribed stones.
What’s not in the traditional alphabet: j, k, q, v, w, x, y, z. These letters appear only in loanwords and modern coinages — vóta (vote), zú (zoo), jab (job). For everything native to Irish, the eighteen letters above are the whole set.
The fada
The síneadh fada (“long mark”) is the diagonal stroke over a vowel: á é í ó ú. It is not a stress mark. It is not decorative. It changes the vowel from short to long, and the long version is often a different word entirely.
cat means cat. cát means cake. The fada is the only thing distinguishing them on the page.
A fuller fada lesson with all five vowel pairs and minimal-pair examples is in the editorial queue.
Broad and slender consonants
Irish consonants come in two flavours: broad (leathan) and slender (caol). Which flavour a consonant has depends on which vowel sits next to it. The rule has its own name: caol le caol agus leathan le leathan — slender with slender, broad with broad.
- Broad vowels — a, o, u (and their long forms á, ó, ú)
- Slender vowels — e, i (and their long forms é, í)
A consonant standing next to a broad vowel is pronounced one way; the same consonant next to a slender vowel is pronounced another way entirely. bád (boat, broad b) sounds like “bawd”; béal (mouth, slender b) sounds like “bay-ul.” Same letter, two sounds.
This is the single biggest concept that takes English speakers by surprise. It also explains why every Irish vowel cluster is doing exactly the work it appears to be doing — the seemingly extra vowels are flagging the consonant’s flavour.
A side-by-side comparator widget for broad/slender consonants is in the editorial queue.
Lenition (séimhiú)
Lenition is a softening. In modern spelling, an h is added after a consonant to mark that the consonant has been softened. In older or handwritten Irish, a dot above the letter does the same job.
The trigger for lenition is grammatical, not phonetic. Possessive pronouns trigger it (mo + cat becomes mo chat, “my cat”). Certain prepositions trigger it. The past tense triggers it. The vocative case triggers it. A learner meets lenition the moment they meet possession.
A full lenition lesson with every trigger and worked examples is in the editorial queue.
Next: the carved-stroke alphabet that came before the Roman one — see the companion Ogham page for the four aicme, the medieval letter-names and kennings, ten real stones, and a reverse-drill quiz.