-s
Plural Formation
In Portuguese, most words ending in a vowel simply add -s to become plural. However, unlike English, you must also change the articles and adjectives to match.
How It Works
The -s suffix is the most common plural marker in Portuguese. It is used for nouns ending in:
- Oral Vowels: a, e, i, o, u (e.g., casa → casas)
- Oral Diphthongs: ai, ei, oi, ui, au, eu, ou, éu, ói (e.g., pai → pais, chapéu → chapéus, herói → heróis)
- Nasal Vowels and Diphthongs: ã, ãe (e.g., irmã → irmãs, mãe → mães)
Important Note on Agreement:
In Portuguese, you cannot just pluralize the noun. You must apply adjective agreement and pluralize the definite articles. For example, 'the big house' is a casa grande, but 'the big houses' must be as casas grandes.
Pronunciation Shift (Metafonia):
Sometimes, a closed 'o' sound (like 'go') in the singular becomes an open 'o' sound (like 'door') in the plural, such as in ovo (egg) vs ovos (eggs).
Exceptions to Watch For:
While most vowels just add -s, words ending in consonants (like -r, -s, -z, -l, -m, or invariant -x like o tórax → os tórax) and the ending -ão follow different rules. See -m to -ns plural, consonant plurals, -l plurals, and -ão plural patterns for those specific cases.
Examples (4)
- A casa é nova. / As casas são novas.
The house is new. / The houses are new.
Word by Word: The house is new. / The houses are new.
Notice how the article 'a', the noun 'casa', the verb 'é', and the adjective 'nova' all change to their plural forms.
- O livro azul. / Os livros azuis.
The blue book. / The blue books.
Word by Word: The book blue. / The books blues.
For 'livro', we simply add -s. Note that 'azul' follows a different plural rule because it ends in a consonant.
- Meu pai e meus pais.
My father and my parents.
Word by Word: My father and my fathers (parents).
Words ending in diphthongs like 'ai' also simply add -s.
- Um café, por favor. / Dois cafés, por favor.
One coffee, please. / Two coffees, please.
Word by Word: One coffee, please. / Two coffees, please.
Adding -s does not remove or change the graphic accent on the vowel.
Common Mistakes
Forgetting to pluralize the adjective (Agreement Failure).
Os carros vermelho.Os carros vermelhos.In Portuguese, adjectives must always agree in number with the noun they describe.
Applying the -s rule to words ending in -m.
Dois homems.Dois homens.Words ending in -m must change the -m to -ns. You cannot simply add -s.
Adding -es to words ending in -u (Spanish interference).
Os perues.Os perus.Unlike Spanish, Portuguese words ending in -u usually just take an -s.
How It Connects
Related Patterns
- Adjective Agreement
Pluralizing a noun is useless if you don't also pluralize the adjectives describing it.
Foundations - o/a/os/asDefinite Articles
Articles must change to 'os' or 'as' to match plural nouns.
Foundations - -m/-nsPlural of -m Nouns
This is the next most common plural rule for nouns ending in the consonant -m.
Level 1 - -ões/-ães/-ãosPlural of -ão Nouns
Nouns ending in -ão are a special category of vowel-ending words with three possible plural forms.
Level 2 - lápis/ônibus/vírusInvariable Plural Nouns
Some nouns already end in -s and do not change at all in the plural.
Level 2
Learn Next
Patterns that build on this one.
- -r/-zPlural of Consonant NounsLevel 1
- meu/minha/meus/minhasPossessive First Person SingularLevel 1
- seu/sua/seus/suasPossessive Third Person and FormalLevel 1
- tenho/tens/tem + anosAge with TerLevel 1
- teu/tua/teus/tuasPossessive Second Person InformalLevel 1
- -ais/-eis/-óis/-uisPlural of -l NounsLevel 2
- guarda-chuva/guarda-chuvasCompound Noun PluralsLevel 2
- muito/poucoMuito/Pouco AgreementLevel 2
Words in This Pattern
Practice -s in Bubblegum
Poppy, your AI tutor, writes Portuguese lessons at your level. Tap any grammar point in a lesson to see its full explanation.
