Prepositions with the Article in Irish

In Brief

When an Irish preposition comes before the definite article (“the”), the two words may stay separate, as in ag an and ar an, or combine, as in i + an → sa/san, de + an → den, do + an → don, and ó + an → ón. The noun that follows often changes at the beginning: ar an mbord (“on the table”), den chéad uair (“for the first time”), and sa charr (“in the car”).

Overview

English simply places a preposition before “the”: “in the house,” “from the shop,” “with the woman.” Irish does more. Some prepositions and the article form a new written unit, and the beginning of the following noun may undergo an initial mutation (a regular change to the first sound and spelling). That is why teach appears unchanged in sa teach, carr becomes charr in sa charr, and bean becomes mbean in leis an mbean.

This is an A2 topic because it builds directly on common prepositions and the definite article. You do not need to memorise every possible phrase at once. First learn the common combinations as chunks: sa/san, den, don, ón, ag an, ar an, and leis an. Then connect each chunk with its usual mutation pattern.

One difference from English is especially important: Irish has no indefinite article equivalent to “a/an.” Compare i dteach (“in a house”) with sa teach (“in the house”). The presence of the Irish definite article changes both the preposition and, in many phrases, the noun.

How It Works

The singular combinations

The singular article is normally an, but several prepositions merge with it. A contraction is simply two words combined into one form.

Basic combination	Form used	Core meaning	Usual effect on a following consonant
i + an	sa / san	in the	lenition with many consonants; no change to d or t
de + an	den	of/from the	lenition
do + an	don	to/for the	lenition
ó + an	ón	from/since the	lenition
ag + an	ag an	at the	eclipsis
ar + an	ar an	on the	eclipsis
faoi + an	faoin	under/about the	eclipsis
le + an	leis an	with the	eclipsis
roimh + an	roimh an	before the	eclipsis
thar + an	thar an	over/past the	eclipsis
trí + an	tríd an	through the	eclipsis

Lenition softens the first consonant and is usually written by adding h: carr → charr, fuinneog → fhuinneog. Eclipsis places another letter in front of the original consonant: bord → mbord, doras → ndoras, gairdín → ngairdín. The original capital remains visible in spelling when a capitalised word is eclipsed, for example i mBaile Átha Cliath.

The table gives the productive standard patterns, but mutation rules have spelling exceptions. The most useful beginner strategy is to learn a whole phrase rather than only an abstract formula.

Choosing between sa and san

Use sa before most consonants:

• sa charr — in the car
• sa siopa — in the shop
• sa teach — in the house

Use san before a vowel and before fh followed by a vowel:

• san oifig — in the office
• san áit — in the place
• san fharraige — in the sea

After sa, many consonants are lenited, but d and t remain unchanged: sa doras, sa teach. A word beginning with s normally remains unchanged after sa: sa seomra, sa siopa. These high-frequency forms are worth learning by sight.

The leniting contractions: den, don, and ón

The contractions den, don, and ón are written as one word. They normally lenite a suitable following consonant:

• den chéad uair — for the first time
• don pháiste — for the child
• ón siopa — from the shop
• ón fhuinneog — from the window

Not every initial letter visibly changes under lenition. In particular, the ordinary spelling rules do not add h after every consonant. Therefore, do not invent a written change merely because a table says “lenition.” Learn the general pattern, then check unfamiliar forms in a dictionary or trusted example.

The eclipsing group

Several prepositions remain recognisable before an, though some alter their ending: faoi → faoin, le → leis an, and trí → tríd an. A following consonant is commonly eclipsed:

• ag an mbanc — at the bank
• ar an mbord — on the table
• faoin gcathaoir — under the chair
• leis an mbean — with the woman
• roimh an gcruinniú — before the meeting
• tríd an doras — through the door

In tríd an doras, d has no distinct visible eclipsed spelling in the standard system, so the noun looks unchanged. Likewise, a vowel normally remains unchanged after these combinations: ag an aerfort (“at the airport”).

A feminine noun (a noun belonging to the feminine grammatical class) beginning with s + vowel, sl, sn, or sr can show t-prefixing rather than ordinary eclipsis in these article phrases: ar an tsráid (“on the street”), leis an tseanbhean (“with the old woman”). Treat these as part of the article system, not as ordinary eclipsis.

What happens in the plural?

The plural definite article is na. Most prepositions simply stand before it: ag na, ar na, leis na, ó na, and so on. The major contractions to learn are:

• i + na → sna: sna tithe — in the houses
• de + na → de na: de na leabhair — of the books
• do + na → do na: do na páistí — for the children

After a preposition plus plural na, the noun normally has no initial mutation: ag na doirse, ar na boird, leis na mná. This makes the plural pattern more straightforward than the singular one. Do not confuse it with other uses of na, such as the plural genitive article, which has its own mutation rules.

A practical decision sequence

When building a phrase, ask four questions:

1. Which preposition expresses the meaning: i, ar, le, ó, and so on?
2. Is the noun definite—are you saying “the house” rather than “a house”?
3. Is the noun singular or plural?
4. Which contraction and mutation belong to that combination?

For “in the car,” choose i, add singular “the,” contract to sa, and lenite carr: sa charr. For “on the tables,” choose ar, add plural na, and leave boird unchanged: ar na boird.

Examples in Context

Irish	English	Note
Tá na heochracha sa charr.	The keys are in the car.	sa + lenition of carr
Tá sí san oifig inniu.	She is in the office today.	san before a vowel
Táimid sa teach anois.	We are in the house now.	No lenition of initial t
D’inis sé an scéal den chéad uair.	He told the story for the first time.	de + an → den
Thug mé an leabhar don pháiste.	I gave the book to the child.	do + an → don
Cheannaigh sí bainne ón siopa.	She bought milk from the shop.	ó + an → ón
Tá sé ag fanacht ag an mbanc.	He is waiting at the bank.	Eclipsis after ag an
Tá an cupán ar an mbord.	The cup is on the table.	Eclipsis after ar an
Tá an cat faoin gcathaoir.	The cat is under the chair.	faoi + an → faoin + eclipsis
Chuaigh mé leis an mbean.	I went with the woman.	le + an → leis an + eclipsis
Buailfimid le chéile roimh an gcruinniú.	We will meet before the meeting.	Eclipsis after roimh an
Shiúil siad tríd an doras.	They walked through the door.	trí + an → tríd an; no visible change to d
Tá cónaí uirthi ar an tsráid seo.	She lives on this street.	Feminine sráid takes t-
Tá na páistí sna tithe.	The children are in the houses.	Plural i + na → sna
Labhair mé leis na múinteoirí.	I spoke with the teachers.	Plural na; no mutation

Common Mistakes

Keeping i an as two words

• Wrong: i an teach
• Right: sa teach
• Why: Before singular an, the preposition i is replaced by sa or san. The choice here is sa because teach begins with a consonant.

Using sa before a vowel

• Wrong: sa oifig
• Right: san oifig
• Why: Use san before a vowel (and before fh plus a vowel).

Adding lenition after sa to every consonant

• Wrong: sa theach
• Right: sa teach
• Why: Initial t and d are not lenited after sa. Memorise sa teach as a model phrase.

Forgetting eclipsis after ar an or leis an

• Wrong: ar an bord; leis an bean
• Right: ar an mbord; leis an mbean
• Why: These combinations normally eclipse a following consonant. English spelling habits offer no reminder, so practise the entire sound-and-spelling chunk.

Using a singular contraction with plural na

• Wrong: don páistí; sa tithe
• Right: do na páistí; sna tithe
• Why: don and sa contain singular an. With plural na, use do na and the special contraction sna.

Mutating a plural noun after a preposition plus na

• Wrong: ag na ndoirse (when meaning “at the doors”)
• Right: ag na doirse
• Why: In an ordinary prepositional phrase, plural na is normally followed by the unmutated noun. Eclipsis with na belongs to other grammatical environments, especially the plural genitive.

Usage Notes

These combinations are not optional contractions or informal shortcuts. Forms such as sa, den, don, and ón are the normal standard forms in both speech and writing. The accent in ón matters: ón siopa means “from the shop,” while on without the accent is not the standard form of this contraction.

Irish varieties differ in pronunciation and sometimes in the forms preferred in everyday speech. You may also encounter older or dialectal dative forms of nouns after prepositions. For general learning and writing, use the standard combinations presented here, while accepting that native speech may sound different from a word-for-word reading of the spelling.

Meaning also depends on the preposition, not only on the contraction. For example, ón Luan can mean “from Monday” or “since Monday” according to context, while den obair can express “of the work” or “from the work.” Learn each phrase inside a complete sentence.

Beyond the Basics / Advanced Use

You do not need to master the following details at A2, but they explain forms you will meet later.

Proper place names sometimes contain an article, and the preposition combines with that article just as it does with an ordinary noun: sa Fhrainc (“in France”) and ón Spidéal (“from Spiddal”). Other place names have no article and follow the mutation rules of a bare preposition instead. This is why a good dictionary entry or map label is useful: English does not reliably tell you whether the Irish name contains an article.

The article also interacts with grammatical gender. The clearest sign in this topic is feminine s-initial nouns such as sráid, giving ar an tsráid. At a more advanced level, gender, case, and dialect can explain apparently competing forms. Case means the form or grammatical role associated with a noun in a phrase; modern standard Irish preserves only parts of an older case system, but fixed expressions and dialects retain more traces of it.

Finally, not every English “preposition + the” maps neatly onto one Irish preposition. Irish often packages meanings differently. For instance, possession, feelings, and states frequently use prepositional constructions where English uses “have” or “be.” The article and mutation rules remain regular inside those larger patterns, but choosing the correct preposition requires learning the Irish expression itself rather than translating one word at a time.

Practice Tips

1. Learn in three mutation families. Make cards for sa/san, the leniting set den/don/ón, and the eclipsing set ag an/ar an/faoin/leis an. Say the whole phrase aloud: ar an mbord, not merely ar an.
2. Transform singular into plural. Change sa teach to sna tithe, don pháiste to do na páistí, and leis an mbean to leis na mná. This reinforces both the article and the disappearance of singular mutation patterns.
3. Describe a real room or route. Use objects around you: ar an mbord, faoin gcathaoir, sa chistin. Then describe where you came from and where you are going, using ón and don in short, meaningful sentences.

Related Concepts

• Prerequisite: Simple Prepositions — learn the basic meanings of ag, ar, de, do, i, le, and ó before combining them with the article.