Regular Plural Formation | Portuguese (Portugal) Grammar

Most Portuguese nouns form their plural predictably. The rules branch on how the singular ends — vowel, consonant, or diphthong — and once you know which bucket a word falls into, the plural is automatic. This page covers the regular, everyday cases. The three trickier families (nouns in -ão, -l, and -m) each have their own dedicated pages because they involve more than just adding a letter.

Before diving in, remember that Portuguese articles and adjectives must agree in number with the noun: o livro grande → os livros grandes, a casa pequena → as casas pequenas. The plural of a noun isn't just about the noun itself — every word around it changes too.

Rule 1: vowel endings take -s

If a noun ends in an unstressed vowel — -a, -e, -i, -o, or -u — the plural simply adds -s. This is the cleanest, most common rule in the whole system.

Singular	Plural	Meaning
o livro	os livros	the book(s)
a casa	as casas	the house(s)
a mesa	as mesas	the table(s)
o estudante	os estudantes	the student(s)
o ovo	os ovos	the egg(s)
o júri	os júris	the jury/juries
o táxi	os táxis	the taxi(s)

Os livros que comprei ontem já estão em cima da mesa.

The books I bought yesterday are already on the table.

As casas naquela rua foram todas construídas nos anos 60.

The houses on that street were all built in the 1960s.

Os estudantes chegam às nove e saem às cinco.

The students arrive at nine and leave at five.

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This rule is so regular that it feels boring — which is exactly why it's worth internalising first. Most Portuguese nouns you'll meet as a beginner fall into this category.

Rule 2: consonant endings (-r, -s, -z) take -es

If a noun ends in -r, -s, or -z, the plural adds -es. You add a whole syllable rather than just a letter, because Portuguese doesn't tolerate consonant clusters at word end the way English does.

Singular	Plural	Meaning
a flor	as flores	the flower(s)
a cor	as cores	the colour(s)
o professor	os professores	the teacher(s)
o mês	os meses	the month(s)
o país	os países	the country/countries
o português	os portugueses	the Portuguese (people)
a luz	as luzes	the light(s)
o rapaz	os rapazes	the boy(s)
a vez	as vezes	the time(s) / occasion(s)

As flores do jardim abriram depois das primeiras chuvas.

The flowers in the garden opened after the first rains.

Os meses de janeiro e fevereiro são os mais frios do ano.

January and February are the coldest months of the year.

Os rapazes estão no pátio a jogar à bola.

The boys are in the yard playing football.

A note on written accents

Nouns ending in stressed -ês lose the circumflex in the plural because the stressed vowel is no longer on the final syllable:

o mês → os meses (not *meses with accent)
o português → os portugueses
o inglês → os ingleses
o francês → os franceses

Some nouns with a stressed final vowel plus -s keep their accent across the plural because the plural form still places stress on that vowel:

o país → os países (the accent stays on the í)
o avô ("grandfather") → os avôs — while avó ("grandmother") → avós. The plural os avós also serves as the gender-neutral "grandparents".

Os meus avós são do norte de Portugal.

My grandparents are from the north of Portugal.

These are small spelling details, but they are part of "getting the plural right" — a teacher will mark them as errors.

Rule 3: diphthong endings take -s

Nouns ending in a diphthong — that is, two vowels pronounced as a single syllable, like -au, -éu, -éi, -ói, -ui, -ai, -oi — form the plural with a simple -s.

Singular	Plural	Meaning
o céu	os céus	the sky/skies
o pai	os pais	the father(s) / parents
o rei	os reis	the king(s)
o herói	os heróis	the hero(es)
a lei	as leis	the law(s)
o boi	os bois	the ox/oxen
o chapéu	os chapéus	the hat(s)

Os meus pais moram no Algarve há dez anos.

My parents have lived in the Algarve for ten years.

Os céus estavam limpos quando partimos de manhã.

The skies were clear when we left in the morning.

Na história, os heróis quase sempre vencem os vilões.

In the story, the heroes almost always defeat the villains.

Note how the accent stays in the plural: herói → heróis, chapéu → chapéus. The pronunciation of the diphthong doesn't change, so the accent mark remains.

Rule 4: nouns ending in -n (rare, foreign)

Portuguese has a small group of foreign-origin nouns ending in -n, and they take -es in the plural, with the -n- becoming part of a new syllable. The most common one you'll meet is o íman (magnet).

Singular	Plural	Meaning
o íman	os ímanes	the magnet(s)
o hífen	os hífenes	the hyphen(s)
o líquen	os líquenes	the lichen(s)
o abdómen	os abdómenes	the abdomen(s)

Os ímanes que puseste no frigorífico caíram todos.

The magnets you put on the fridge all fell off.

These are low-frequency words for a beginner, but you should recognize the pattern so the plurals don't surprise you.

Rule 5: nouns in unstressed -s are invariable

Portuguese nouns whose final -s falls in an unstressed syllable are invariable — they have the same form in the singular and the plural. The only thing that changes is the article and any surrounding agreement.

Singular	Plural	Meaning
o lápis	os lápis	the pencil(s)
o ónus	os ónus	the burden(s)
o oásis	os oásis	the oasis/oases
o vírus	os vírus	the virus(es)
o pires	os pires	the saucer(s)

For contrast, multi-syllable nouns whose final -s falls in a stressed syllable take -es normally: o mês → os meses, o país → os países, o rapaz → os rapazes. The invariable class is specifically those polysyllabic nouns whose final -s is unstressed.

Empresta-me um dos teus lápis, o meu partiu-se.

Lend me one of your pencils, mine broke.

Os vírus mais recentes propagam-se pelas redes sociais.

The most recent viruses spread via social networks.

Note that the underlying principle is phonological: Portuguese avoids adding an extra syllable to words that are already short and end in -s. Multi-syllable nouns in -s (like o mês → os meses) are not invariable — they follow the -es rule above.

Rule 6: nouns ending in -x are invariable

Nouns ending in -x are rare but invariable in the plural.

Singular	Plural	Meaning
o tórax	os tórax	the thorax/thoraces
o fénix	os fénix	the phoenix(es)
o xerox	os xerox	the photocopy/photocopies

Os tórax dos insetos são divididos em três segmentos.

Insect thoraxes are divided into three segments.

Putting the rules together

Here's a compact summary you can keep in your head:

Singular ends in	Add	Example
-a, -e, -i, -o, -u (vowel)	-s	livro → livros
-r, -s (multi-syllable), -z	-es	flor → flores
diphthong (-au, -éu, -ai, -ei, -oi, -ui)	-s	pai → pais
-n	-es (with vowel insertion)	íman → ímanes
-s (single syllable)	no change	lápis → lápis
-x	no change	tórax → tórax
-ão	see dedicated page	pão → pães
-l	see dedicated page	animal → animais
-m	-ns	homem → homens

Articles and adjectives pluralise too

Every time a noun goes plural, its article and adjectives pluralise with it. This is Portuguese agreement in action:

o livro novo → os livros novos
a casa grande → as casas grandes
um amigo simpático → uns amigos simpáticos
uma amiga inteligente → umas amigas inteligentes

Os meus amigos portugueses são muito simpáticos.

My Portuguese friends are very nice.

As casas velhas da aldeia têm paredes grossas.

The old houses in the village have thick walls.

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When you're checking a sentence, count the plural markers. For every plural noun, you should see a plural article, and any adjectives around it should be plural too. Missing a single -s is one of the most common error patterns in learners' writing.

What this page does not cover

Three families of plurals need their own treatment because they don't fit the "add -s" / "add -es" logic:

Nouns in -ão (like pão, coração, mão) can take -ães, -ões, or -ãos in the plural depending on the word. This three-way branch has its own dedicated page.
Nouns in -l (like animal, papel, hotel) drop the -l and add -is (animais, papéis, hotéis). See the -l plurals page.
Nouns in -m (like homem, jardim, fim) change -m to -ns (homens, jardins, fins). This follows a fixed pattern too specific for this page.

Learn the rules on this page first, then pick up the -ão family, which is by far the most important of the three special cases.

Common Mistakes

❌ Os flors do jardim são bonitas.

Incorrect — *flor* ends in -r, so the plural is *flores*, not *flors*.

✅ As flores do jardim são bonitas.

The garden flowers are beautiful.

❌ Os portuguêses gostam de bacalhau.

Incorrect — when *português* becomes plural, the circumflex drops: *portugueses*.

✅ Os portugueses gostam de bacalhau.

The Portuguese like codfish.

❌ Comprei dois pais na padaria.

Incorrect — this would mean 'I bought two fathers,' since *pão* → *pães* (the bread plural is irregular and covered on the -ão plurals page).

✅ Comprei dois pães na padaria.

I bought two bread rolls at the bakery.

❌ Os lápises estão em cima da mesa.

Incorrect — *lápis* is invariable; the plural is identical to the singular.

✅ Os lápis estão em cima da mesa.

The pencils are on the table.

❌ O meu amigos novos moram em Lisboa.

Incorrect — the article and adjective must pluralise with the noun.

✅ Os meus amigos novos moram em Lisboa.

My new friends live in Lisbon.

Once you've got the regular plurals solid, the most important special case to learn next is the -ão plural branches — they cover a huge portion of everyday vocabulary.