Basic Adjectives in Irish

In Brief

An Irish adjective usually comes after the noun it describes: fear mór, “a big man.” An adjective beside a feminine singular noun is normally lenited, so mór becomes mhór in bean mhór, “a big woman.” With plural nouns, the adjective normally has a plural form, such as fir mhóra, “big men.”

Overview

An adjective is a describing word such as “big,” “good,” or “young.” In English, it usually comes before its noun: “a big house.” In Irish, the basic order is the reverse: teach mór. This noun-first pattern is the most important beginner rule.

Irish adjectives also show agreement: their form can reflect the gender and number of the noun. Gender means that a noun belongs to the masculine or feminine grammatical class; number means singular or plural. A masculine singular noun generally takes the basic adjective, while a feminine singular noun usually causes lenition (séimhiú, the initial change often written by adding h): fear beag but bean bheag.

This is an A1 topic, but it connects to several larger parts of Irish grammar. To choose the right adjective form reliably, you need to know a noun's gender and plural. Later, case—a change that marks a noun's grammatical role—also affects adjectives. Begin with ordinary singular and plural phrases; the later details are separated below.

How It Works

The beginner pattern

For an ordinary noun phrase, start with these three steps:

1. Put the noun first and the adjective after it.
2. If the noun is feminine singular, lenite the adjective when possible.
3. If the noun is plural, use the adjective's plural form.

Irish	English	Pattern
fear mór	a big man	masculine singular: basic adjective
bean mhór	a big woman	feminine singular: lenition
fir mhóra	big men	plural adjective; lenited after slender-final fir
mná móra	big women	plural adjective; no lenition after a vowel

The mutation belongs to the relationship between noun and adjective. The adjective is not permanently changed: dictionary entries list mór, not mhór.

Adjectives normally follow nouns

The usual pattern is:

noun + adjective

• teach nua — a new house
• leabhar maith — a good book
• oíche fhuar — a cold night
• cathair mhór — a big city

English word order is a common source of errors. Do not build “big house” as adjective + noun; say teach mór.

A few very common adjectives and adjective-like words can occur before nouns in fixed grammatical patterns, but they are not the basic pattern taught here. For everyday description, noun + adjective is the safe starting point.

Masculine and feminine singular nouns

With a masculine singular noun in the ordinary subject form, the following adjective normally stays in its basic form:

• fear maith — a good man
• bord beag — a small table
• leabhar suimiúil — an interesting book

With a feminine singular noun, the adjective is normally lenited:

• bean mhaith — a good woman
• fuinneog bheag — a small window
• oíche chiúin — a quiet night

Lenition is visible only when the initial letter can take it. The common written changes relevant here include b → bh, c → ch, d → dh, f → fh, g → gh, m → mh, p → ph, s → sh, and t → th. An adjective beginning with a vowel, or with a consonant that does not lenite, may look unchanged:

• bean álainn — a beautiful woman
• oíche iontach — a wonderful night
• bean rua — a red-haired woman

The lack of an h in these phrases does not make the noun masculine. It simply means that the adjective's first sound has no applicable written lenition in this position.

Forming the plural adjective

Irish plural formation is not completely uniform. Many common adjectives add -a or -e, sometimes with a spelling adjustment that keeps broad and slender consonants properly matched.

Basic form	Plural form	Example	Meaning
mór	móra	tithe móra	big houses
beag	beaga	báid bheaga	small boats
deas	deasa	daoine deasa	nice people
óg	óga	cailíní óga	young girls
maith	maithe	leabhair mhaithe	good books
ciúin	ciúine	sráideanna ciúine	quiet streets

Learn a noun's plural and an adjective's plural together through complete phrases. A spelling rule alone will not predict every form.

Plural lenition has an additional pattern. When the plural noun ends in a slender consonant—a consonant whose nearest vowel is e or i—the following adjective is generally lenited. Compare:

• fir mhóra — big men: fir ends in slender r
• leabhair mhaithe — good books: leabhair ends in slender r
• báid bheaga — small boats: báid ends in slender d
• tithe móra — big houses: tithe ends in a vowel, so no lenition
• cailíní óga — young girls: cailíní ends in a vowel

For A1 work, it is enough to recognise and practise common phrases such as fir mhóra. Do not delay speaking while trying to derive every plural form in real time.

Attributive and predicative descriptions

An attributive adjective sits directly beside its noun: “a big woman,” bean mhór. It agrees with that noun.

A predicative adjective describes the subject after a verb: “the woman is big.” With tá, Irish uses the basic adjective form rather than feminine or plural agreement:

• Tá an fear mór. — The man is big.
• Tá an bhean mór. — The woman is big.
• Tá na fir mór. — The men are big.

This difference is important: bean mhór is one noun phrase, but in Tá an bhean mór, the adjective is a separate predicate (what is being said about the woman). English does not show this contrast in the adjective itself.

More than one adjective

Several adjectives can follow one noun. Each adjective belongs to the noun and normally shows the relevant agreement:

• fear mór cairdiúil — a big, friendly man
• bean bheag chiúin — a small, quiet woman
• leabhair mhóra shuimiúla — big, interesting books

In natural speech, agus (“and”) can make a longer description easier to process: fear mór agus cairdiúil, “a big and friendly man.”

Examples in Context

Irish	English	Note
Tá fear mór ag an doras.	There is a big man at the door.	Masculine singular fear
Chonaic mé bean mhór sa siopa.	I saw a big woman in the shop.	Feminine singular causes lenition
Is leabhar maith é.	It is a good book.	Basic form after masculine leabhar
Is scéal suimiúil é.	It is an interesting story.	Adjective follows the noun
Tá fuinneog bheag sa seomra.	There is a small window in the room.	Feminine fuinneog lenites beag
Bhí oíche fhuar againn.	We had a cold night.	Feminine oíche lenites fuar
Tá an cailín óg.	The girl is young.	Predicate after tá: basic form
Is cailín óg í.	She is a young girl.	óg begins with a vowel
Tá fir mhóra ag obair anseo.	Big men are working here.	Plural after slender-final fir
Cheannaigh sí leabhair mhaithe.	She bought good books.	Plural maithe, with lenition
Tá tithe móra ar an tsráid.	There are big houses on the street.	No lenition after vowel-final tithe
Tá cailíní óga sa rang.	There are young girls in the class.	Plural óga after a vowel
Chonaic mé báid bheaga sa chuan.	I saw small boats in the harbour.	Slender-final plural triggers lenition
Is bean bheag chiúin í.	She is a small, quiet woman.	Both adjectives agree with bean

Common Mistakes

Putting the adjective before the noun

• Wrong: mór teach
• Right: teach mór
• Why: Ordinary descriptive adjectives normally follow their nouns in Irish. English order does not transfer directly.

Forgetting lenition after a feminine singular noun

• Wrong: bean mór
• Right: bean mhór
• Why: A directly attached adjective is normally lenited after a feminine singular noun.

Leniting every feminine adjective mechanically

• Wrong: bean hálainn
• Right: bean álainn
• Why: Vowel-initial adjectives do not take ordinary lenition. Learn both the trigger and which initial letters can actually change.

Using singular adjectives with plural nouns

• Wrong: fir mhór
• Right: fir mhóra
• Why: The adjective needs its plural form. Here it is also lenited because fir ends in a slender consonant.

Leniting after every plural noun

• Wrong: tithe mhóra
• Right: tithe móra
• Why: The adjective is plural, but ordinary plural lenition is associated with a noun ending in a slender consonant. Tithe ends in a vowel.

Carrying attributive agreement into a predicate

• Wrong: Tá an bhean mhór. when you mean “The woman is big.”
• Right: Tá an bhean mór.
• Why: A predicate adjective after tá uses the basic form. An bhean mhór as a complete noun phrase means “the big woman.”

Usage Notes

In everyday Irish, adjective agreement is not optional decoration: mutations and endings help listeners recognise how words belong together. At the same time, dialects can differ in pronunciation and in the strength with which some traditional distinctions are maintained. The written standard provides a useful shared model, and the patterns in this article follow that model.

Some English descriptions are expressed more naturally by another Irish construction. For temporary states and many general descriptions, Irish often uses tá plus a predicate adjective: Tá sí tuirseach, “She is tired.” Classification or identification may instead use the copula is: Is bean chineálta í, “She is a kind woman.” Do not assume that every English “be + adjective” sentence maps word for word onto one Irish pattern.

Adjectives can also become adverbs with go, describing how an action happens rather than describing a noun: maith (“good”) but go maith (“well”), and álainn (“beautiful”) but go hálainn (“beautifully”). This is a different pattern, so noun agreement does not apply: Canann sí go maith, “She sings well.”

Beyond the Basics / Advanced Use

You do not need to master this section at A1, but these patterns explain forms you will meet in careful writing and more advanced courses.

Case changes

Irish retains a genitive case, used especially in “of” relationships and after some verbal-noun constructions. Nouns and their adjectives may both change in the genitive, and the pattern depends on gender, number, and declension class. For example, fear mór can appear as an fhir mhóir in “of the big man.” The adjective mór becomes mhóir here.

This cannot be reduced to the beginner rule “feminine causes lenition.” In the genitive, masculine and feminine patterns differ from their ordinary subject forms. Learn these systematically with the Genitive Case, rather than guessing from nominative phrases.

Adjectives with irregular or less predictable forms

Not every adjective makes its plural or comparative by simply adding an ending. Some common adjectives have spelling changes, and comparison can use a distinct form: maith (“good”) has níos fearr (“better”), while mór has níos mó (“bigger”). These belong to the later system of comparatives and superlatives.

Fixed position and meaning

Although most descriptive adjectives follow the noun, a small group occurs before nouns in established expressions. Position can be tied to a special grammatical meaning rather than free stylistic choice. Treat these expressions as separate patterns; do not generalise from them and begin placing ordinary adjectives before nouns.

Dialect and traditional forms

You may hear differences among Connacht, Munster, and Ulster Irish, especially in pronunciation and in particular inflected forms. For a learner, the most useful approach is to use standard written agreement while listening closely to the variety spoken in the material or community you follow.

Practice Tips

1. Learn phrases, not isolated words. Record each adjective with a masculine noun, a feminine noun, and a plural: fear mór, bean mhór, fir mhóra. This makes agreement audible and memorable.
2. Transform one phrase at a time. Take teach beag and change the noun: fuinneog bheag, tithe beaga, báid bheaga. Say why each adjective changes—or does not.
3. Contrast phrase and sentence. Practise pairs such as an bhean mhór (“the big woman”) and Tá an bhean mór (“the woman is big”). This prevents one of the most persistent agreement errors.

Related Concepts

• Prerequisite: Gender of Nouns — explains why fear and bean trigger different adjective forms
• Next step: Colours — applies adjective agreement to common colour words
• Next step: Describing People — combines adjectives with natural patterns for appearance and personality
• Later study: Comparatives and Superlatives — develops forms such as “bigger,” “better,” and “the tallest”