By the time you reach this page you already know the workhorse plural rules: -s on vowels, -is on -l words, -ns on -m words, and the three -ão patterns. What's left are the genuinely irregular corners — words ending in -r, -z, -s, and -x; diminutives that pluralize in two places at once; compound nouns where only some parts move; foreign borrowings; and a small club of words that are always plural and have no singular at all. These are B1 territory because they require you to combine rules and, in several cases, override your instincts.
Nouns ending in -r, -z (add -es)
Words ending in -r and -z add -es — they need a vowel to carry the plural -s, and -es supplies it.
| Singular | Plural | Meaning |
|---|---|---|
| mar | mares | sea(s) |
| flor | flores | flower(s) |
| mulher | mulheres | woman/women |
| cor | cores | color(s) |
| luz | luzes | light(s) |
| cruz | cruzes | cross(es) |
| rapaz | rapazes | young man/men |
As flores do jardim já estão começando a murchar com o calor.
The flowers in the garden are already starting to wilt in the heat.
Apaga as luzes quando sair, por favor.
Turn off the lights when you leave, please.
Nouns ending in -s: invariable or +es
Words ending in -s split by stress, just as a logical extension of everything else.
Stressed final syllable → add -es: mês → meses, país → países, ananás → ananases (pineapple).
Unstressed final syllable → invariable: the singular and plural are spelled identically, and only the article shows the number. This is where lápis, ônibus, vírus, and atlas live.
| Type | Singular | Plural | Meaning |
|---|---|---|---|
| stressed | o mês | os meses | month(s) |
| stressed | o país | os países | country/countries |
| invariable | o lápis | os lápis | pencil(s) |
| invariable | o ônibus | os ônibus | bus(es) |
| invariable | o vírus | os vírus | virus(es) |
Perdi os dois lápis que comprei ontem.
I lost both pencils I bought yesterday.
Os ônibus dessa linha passam de dez em dez minutos.
The buses on this route come every ten minutes.
Nouns ending in -x: invariable
Words ending in -x are invariable — they don't change form at all. O tórax → os tórax, o ônix → os ônix, a fênix → as fênix. Like the unstressed -s words, the article does the work.
Os tórax dos pacientes foram examinados por raio-x.
The patients' chests were examined by X-ray.
Diminutives: BOTH parts pluralize
This is the showpiece irregularity and the one English speakers find most surprising. When a diminutive is formed with -zinho/-zinha (the form added with a linking z), the plural is built by pluralizing the base noun first, dropping its final -s, and then adding -zinhos/-zinhas. The result is that the plural marker appears twice — once inside the stem and once at the end.
Take it step by step with pão:
- Plural of pão is pães.
- Drop the final -s: pãe-.
- Add -zinhos: pãezinhos.
| Singular dim. | Plural dim. | From |
|---|---|---|
| pãozinho | pãezinhos | pão → pães |
| florzinha | florezinhas | flor → flores |
| animalzinho | animaizinhos | animal → animais |
| colherzinha | colherezinhas | colher → colheres |
| papelzinho | papeizinhos | papel → papéis |
| cãozinho | cãezinhos | cão → cães |
A vó comprou uns pãezinhos quentinhos para o café da manhã.
Grandma bought some warm little bread rolls for breakfast.
As crianças desenharam florezinhas coloridas no caderno.
The kids drew little colorful flowers in their notebook.
Adotamos dois animaizinhos do abrigo no fim de semana.
We adopted two little animals from the shelter over the weekend.
Notice how the accent inside the stem is dropped once it's no longer the stressed syllable: papéis loses its accent in papeizinhos because the stress has moved onto the -zinhos suffix. The logic is that the diminutive suffix takes over as the stressed element, so the original accent on the stem disappears.
Compound nouns: only some parts move
Compound nouns are a topic in their own right (see the dedicated page), but the plural essentials are these. In a noun + noun or noun + adjective compound, both elements typically pluralize: couve-flor → couves-flores, segunda-feira → segundas-feiras, obra-prima → obras-primas. When the first element is a verb or an invariable word, it stays fixed and only the noun pluralizes: guarda-chuva → guarda-chuvas (verb guarda + noun chuva), beija-flor → beija-flores (verb beija + noun flor).
| Singular | Plural | Meaning | What moves |
|---|---|---|---|
| guarda-chuva | guarda-chuvas | umbrella(s) | only the noun |
| beija-flor | beija-flores | hummingbird(s) | only the noun |
| segunda-feira | segundas-feiras | Monday(s) | both parts |
| couve-flor | couves-flores | cauliflower(s) | both parts |
| obra-prima | obras-primas | masterpiece(s) | both parts |
Esqueci dois guarda-chuvas no escritório na semana passada.
I left two umbrellas at the office last week.
Não trabalho às segundas-feiras.
I don't work on Mondays.
Os beija-flores aparecem no jardim toda manhã.
The hummingbirds show up in the garden every morning.
Foreign borrowings
Established loanwords usually take a plain Portuguese -s, often after being respelled into Portuguese norms: pizza → pizzas, blog → blogs, clube → clubes, gol → gols (the soccer-goal word, spelled the Brazilian way). Less-assimilated borrowings sometimes keep their foreign plural in writing (show → shows, e-mail → e-mails), and you'll see variation in how formally a text treats them.
Pedimos duas pizzas grandes porque estávamos com muita fome.
We ordered two large pizzas because we were really hungry.
A banda fez três shows lotados em São Paulo.
The band played three sold-out shows in São Paulo.
Always-plural words (pluralia tantum)
Some nouns exist only in the plural and have no everyday singular — using them in the singular sounds wrong or means something different. The high-frequency ones:
| Word | Meaning |
|---|---|
| os óculos | glasses/eyeglasses |
| as férias | vacation/holidays |
| os parabéns | congratulations |
| as costas | (one's) back |
| os arredores | surroundings/outskirts |
Perdi os óculos de novo — você viu onde deixei?
I lost my glasses again — did you see where I left them?
As férias do meio do ano sempre passam rápido demais.
The mid-year vacation always goes by far too fast.
Estou com dor nas costas de tanto carregar caixa.
My back hurts from carrying so many boxes.
A note for English speakers: English shares this quirk with words like glasses, scissors, trousers, congratulations. The trap isn't the concept — it's that the lists don't match. Portuguese óculos and férias are always plural, but Portuguese says uma calça (a pair of trousers) in the singular, exactly opposite to English. Don't assume a word is pluralia tantum just because its English equivalent is.
Common Mistakes
❌ Comprei dois pãozinhos.
Incorrect — diminutive plural must double-mark: pãezinhos
✅ Comprei dois pãezinhos.
I bought two little bread rolls.
❌ Os lápises estão na mochila.
Incorrect — unstressed -s word is invariable; only the article changes
✅ Os lápis estão na mochila.
The pencils are in the backpack.
❌ Não trabalho às segunda-feiras.
Incorrect — in segunda-feira both parts pluralize
✅ Não trabalho às segundas-feiras.
I don't work on Mondays.
❌ O óculo está sujo.
Incorrect — óculos is always plural
✅ Os óculos estão sujos.
The glasses are dirty.
❌ Os guardas-chuvas estão na entrada.
Incorrect — guarda is a verb here, so only the noun pluralizes: guarda-chuvas
✅ Os guarda-chuvas estão na entrada.
The umbrellas are at the entrance.
The thread connecting these is that each requires you to think about structure rather than reflexively add -s: Is the -s word stressed (so it inflects) or not (so it's invariable)? Is the compound's first element a noun (it moves) or a verb (it stays)? Does the diminutive need its hidden second plural? B1 plurals reward the learner who pauses to parse the word before pluralizing it.
Key Takeaways
- -r/-z words add -es (flor → flores, luz → luzes).
- -s words: stressed → -es (mês → meses); unstressed → invariable (o lápis → os lápis).
- -x words are invariable (o tórax → os tórax).
- Diminutives double-pluralize: pãozinho → pãezinhos, florzinha → florezinhas, animalzinho → animaizinhos.
- Compounds: both parts move unless the first is a verb/invariable (segundas-feiras but guarda-chuvas).
- Borrowings usually take -s (pizzas, shows); some words are always plural (óculos, férias, parabéns).
Now practice Portuguese
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Portuguese→Related Topics
- Plural of -ÃO Ending WordsA2 — The three plural patterns for nouns ending in -ão — the default -ões plus the memorized sets -ães and -ãos — and why -ões is the safe bet when you're unsure.
- Plural of -L Ending WordsA2 — How nouns ending in -l drop the -l and add -is, the accents this creates (papéis, lençóis), and the stress split that decides whether -il becomes -is or -eis.
- Compound NounsB1 — How Brazilian Portuguese builds compound nouns from noun+noun, verb+noun, and prepositional patterns — and the unpredictable rules for pluralizing each type.
- Diminutives: -inho, -inhaA1 — How to form Brazilian Portuguese diminutives — when to use -inho/-inha vs -zinho/-zinha, the spelling changes that protect the stem, and how to pluralize them.
- Plural of -M Ending WordsA2 — The fully regular -m → -ns plural — homem→homens, jardim→jardins, som→sons, álbum→álbuns — and why the spelling change just reflects the nasal sound staying put.