Essential Grammar Patterns

Irish grammar has a reputation, but most of what you meet as a beginner comes down to ten repeating patterns. Learn to recognise them and a page of Irish stops looking like a puzzle.

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1. Séimhiú — the Little "h"

Sometimes a word picks up an h after its first letter: b becomes bh, c becomes ch, s becomes sh. That h is a softening, and it is triggered by the word in front.

• after mo (my) and do (your)
• after a meaning "his"
• after an (the) when the noun is feminine

bean (woman) is feminine, so "the woman" is an bhean. You can see why the dictionary tells you a noun's gender: it decides whether this happens.

2. Urú — a New Letter at the Front

The other change adds a letter in front of the word, with the original letter still written — just no longer said on its own:

b → mb  ·  c → gc  ·  d → nd  ·  f → bhf  ·  g → ng  ·  p → bp  ·  t → dt

Words that begin with a vowel take n- instead. You meet this pattern after words like i (in) — and in Munster after ag an and ar an as well, which is why bord becomes ar an mbord (on the table) there. The dialects differ on this one, as our guide to the dialects explains.

3. The Verb Comes First

Irish sentences run verb — who — what: D'ith mé an t-arán (ate — I — the bread). English puts the person first; Irish does not. This is the single most useful pattern on the page, and Part 2 of this series takes it apart step by step.

4. Past Tense

To talk about something that has already happened, regular verbs take a softening on the first letter: bris (break) becomes bhris — Bhris mé (I broke). Verbs that begin with a vowel — or with f — take d' instead: D'ól sí (she drank), D'ith sé (he ate), D'fhág mé (I left).

A handful of common verbs do not follow this at all and simply change shape: chonaic (saw), tháinig (came), rinne (did, made), fuair (got), dúirt (said). They are worth memorising as whole words — they are in Part 1 of this series.

5. Present Tense

Most verbs in the present tense end in -ann or -íonn: itheann sé (he eats), ólann sí (she drinks), scríobhann siad (they write). In the first person you will also hear a shorter ending — ólaim (I drink), ithim (I eat) — alongside the longer forms.

6. Question Words

These are worth learning as shapes rather than translations, because the answer usually echoes the question word: ask Cá? and the reply will begin with a place word.

7. Possessives — Who Owns It

Watch the changes in this table. Two of the words are spelled a and mean different things, and different ones of these trigger a séimhiú or an urú.

Mo and do soften the noun; a meaning "her" does not; ár, bhur and a meaning "their" add the extra letter instead. Reading the vowels of the next word also tells you which a you are looking at.

8. "An" (the) Changes Words Too

• A feminine noun picks up an h: cathaoir (chair) becomes an chathaoir.
• A masculine noun beginning with a vowel takes t-: arán (bread) becomes an t-arán.

So the article "the" is not just a word you learn once — it changes the word after it, and the change tells you something about the noun.

9. Plurals

There is no single plural ending, but there are three you will see most:

• -í added to the word: bosca → boscaí (boxes)
• a changed ending: leabhar → leabhair (books)
• -anna on longer words: ceacht → ceachtanna (lessons)

Guessing the plural is not worth the risk — a dictionary entry always shows it, usually in the same line as the gender.

10. The Little Prepositions

Four small words that carry an enormous amount of meaning: ar (on), ag (at — and how you say you have something: tá leabhar agam), le (with, to) and do (to, for).

In Irish they glue themselves to pronouns: ag + mé becomes agam (at me, I have), le + mé becomes liom (with me). Those two — liom and leis — are in Part 1 of this series for exactly this reason.

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You Don't Need the Names

You do not have to remember which pattern is called a séimhiú to read Irish. Notice the shape: an h after the first letter, or an extra letter in front of it. Then ask the more useful question — what word came before it? That is what caused the change, and after a few weeks you will spot it without thinking.

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Previously: Part 2 — Understanding Irish: Sentence Structure

TREORAí

Get familiar with the patterns

Grammatical patterns stick when you meet them regularly and use them regularly. The TREORAí courses introduce each pattern with examples and practice built in, and the reference section lets you look up a form the moment you meet it in the wild.

Then bring it to the conversation: an AI companion that answers in Irish, at your pace, and helps when a sentence goes sideways.

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