Do

Do primarily translates to "to" or "for". It is used to mark the indirect object, express possession with the copula, and indicate closeness or necessity.

Preposition Conjugated Dative

Overview

Forms

Pronoun	Form	Contrast Form	Translation
I	dom	domhsa	to/for me
You	duit	duitse	to/for you
He	dó	dósan	to/for him
She	di	dise	to/for her
We	dúinn	dúinne	to/for us
You (pl)	daoibh	daoibhse	to/for you
They	dóibh	dóibhsean	to/for them

Dialect variations are common. You may hear dhom or damh for “dom”, and dhá for “dá”. In Connemara, short forms like 'om, 'uit are often heard.

Pronoun	Possessive Pronoun	Translation
I	do mo/dom	to my
You	do do/dod	to your
He	dá	to his
She	dá	to her
We	dár	to our
You (pl)	do bhur	to your
They	dá	to their

Mutations

Without an article

Base Do + Seán

Mutated Do Sheán

Rule Lenition

With an article

Base Do + an + máthair

Mutated Don mháthair

Rule Lenition

General Rule — do Sheán — to Seán — do causes lenition on nouns without the article.
With the article (General) — don mháthair — to the mother — do combines with an to form don, causing lenition.
The “S” Rule — don tsagart — to the priest — If the noun begins with s, don causes a t-prefix instead of lenition.
Vowel Start — d’Úna — to Úna — Before a vowel or fh, do becomes d'.

Interrogatives

Question	Meaning	Example
Cé + do	To whom?	Cé dó a thug tú é?
Cad + do	What for?	Cad dó é sin?
Cá + do	Where to?	Cá dó a ndeachaigh sé?

De vs Do

In many dialects, the simple prepositions de (of/off) and do (to/for) sound nearly identical (often pronounced as gə or də). However, their conjugated forms (like díom vs dom) usually remain distinct.

Interaction & Benefit

The Indirect Object

Giving/Telling — thug mé leabhar duit — I gave a book to you — Marking the recipient of an action.
Benefit (For) — rud a dhéanamh duit — to do something for you — When an action is done in someone’s favour.
Wishes — oíche mhaith duit — good night to you — Used in greetings and well-wishing.

Note on Detriment

If an action harms or disadvantages someone, Irish typically uses ar instead of do.

Rinne sé obair dom (He did work for me).
Bhris sé an bord orm (He broke the table on me/to my detriment).

Feelings & Attitude

Attitude — bheith go maith do dhuine — to be good to someone — Expressing kindness or behavior toward others.
Pity — tá trua agam duit — I have pity for you / I feel sorry for you.

Identity & State

Copula Constructions

Naming — Seán is ainm dom — My name is Seán — Lit. “Seán is name to-me.”
Age — Cá haois duit? — What age are you? — Lit. “What age to-you?”
Relationship — is mac dom é — he is a son of mine — Establishing kinship using do (often used with indefinite nouns like “a friend”, “a brother”).
Origin — Is as Éirinn dom — I am from Ireland — Lit. “It is from Ireland to-me” (Using do to identify the person the origin belongs to).

Necessity & Modals

Necessity — b’éigean do — it was necessary for… — Used to express “must” or “had to”.
Obligation — is ceart do — it is right for… — Used to express “should” or “ought”.
Worth — is fiú do — it is worth it for… — Indicating value.

Time & Connection

Temporal Logic

Time — ceathrú don trí — a quarter to three — Marking time remaining until the hour.
Verbal Noun Timing — tar éis é a dhéanamh dom — after I had done it — Lit. “after doing it to-me”. Used to mark the subject (agent) of a verbal noun in time clauses.

Connection & Proximity

Proximity — cóngarach do — close to — Indicating physical closeness.
Relation — gaolmhar do — related to — Indicating family or logical connection.
Exclusive — seomra dom féin — a room for myself — Indicating exclusivity or possession.

Progressive Construction

Action directed at object — tá mé do do bhualadh — I am hitting you — Lit. “I am to your hitting.”
Passive State — tá mé do mo bhualadh aige — I am being hit by him — Lit. “I am to my hitting at-him.”