In short

Every Portuguese noun has a gender - it is either masculine or feminine, even a table or a book - and that gender controls the words around it (the word for “the”, every adjective). It also has a number: singular or plural. English marks only number, so the habit to build now is to learn each noun with its little gender tag o (masculine) or a (feminine) attached, and to know the plural endings, especially for the tricky -ão and consonant words.

The rule

Gender: masculine or feminine

There is no “it” in Portuguese. A thing is o (the, masculine) or a (the, feminine), and you cannot always guess which - so store the article with the word. That said, the endings give strong hints.

Usually masculine: nouns ending in -o (o livro, o carro, o dinheiro). Watch the Greek-origin -ma group, which is also masculine despite the a: o problema, o programa, o tema, o clima. And a few everyday words: o dia, o mapa, o cinema.

Usually feminine: nouns ending in -a (a casa, a mesa, a rua), and reliably these suffixes: -ção / -são (a nação, a televisão), -dade (a cidade, a verdade), -gem (a viagem, a garagem). A useful trap: many -or nouns are masculine (o professor, o amor), but a cor, a dor and a flor are feminine.

Gender of people and animals

For living beings the gender is natural, and there is often a masculine/feminine pair:

• -o -> -a: o menino / a menina, o gato / a gata.
• add -a to a consonant: o professor / a professora, o português / a portuguesa.
• -ão shifts in several ways: o irmão / a irmã, o patrão / a patroa, o leão / a leoa.

Some nouns never change form - only the article does: o estudante / a estudante, o colega / a colega, o jovem / a jovem. And a few keep one fixed gender whoever they describe: a pessoa, a criança, a vítima are always feminine, even for a man.

Number: making nouns plural

The plural ending depends on how the singular ends:

• vowel -> add -s: casa -> casas, livro -> livros, café -> cafés.
• -r, -z, or stressed -s -> add -es: professor -> professores, luz -> luzes, o país -> os países. A word already ending in unstressed -s does not change: o lápis -> os lápis.
• -m -> -ns: homem -> homens, jardim -> jardins, um -> uns.
• -l -> drop the l, add -is: animal -> animais, papel -> papéis, lençol -> lençóis, azul -> azuis. An -el or -il word that already carries a written accent is stressed earlier: the ending is -eis and the accent stays where it is - fácil -> fáceis, móvel -> móveis, nível -> níveis.

The -ão plural (the classic trap)

Nouns in -ão take one of three plurals, and you must simply learn which:

• -ões (the large majority): lição -> lições, coração -> corações, informação -> informações.
• -ães (a small set): pão -> pães, cão -> cães, alemão -> alemães, capitão -> capitães.
• -ãos (add -s, a few common words): mão -> mãos, irmão -> irmãos, cidadão -> cidadãos.

When you meet a new -ão noun, default to -ões; only the short -ães and -ãos lists are exceptions.

Forms & patterns

Common gender signals:

Plural formation:

Examples

Common mistakes

• a problema -> o problema - the Greek -ma nouns are masculine (o tema, o programa, o clima too).
• o cor azul -> a cor azul - a cor, a dor and a flor are feminine even though they end in -or.
• dois irmães -> dois irmãos - not every -ão takes -ães; irmão, mão and cidadão take -ãos.
• três pãos -> três pães - pão, cão and alemão belong to the small -ães group.
• os animales -> os animais - words in -l drop the l and add -is; they never add -es.
• o pessoa (about a man) -> a pessoa - pessoa, criança and vítima stay feminine whoever they refer to.
• os lápises -> os lápis - a word already ending in an unstressed -s does not change in the plural.

Tips

• Learn every noun with its article: store a viagem and o problema, never the bare noun - the gender is part of the word.
• Trust the strong feminine suffixes -ção, -são, -dade and -gem; they almost never let you down.
• For -ão nouns, memorise the two short lists (-ães: pão, cão, alemão; -ãos: mão, irmão, cidadão) and default everything else to -ões.
• To feminise a person, the usual move is -o -> -a or “add -a” to a consonant (menino/menina, professor/professora).
• The article and any adjective must match the noun’s gender and number too, but that is Lessons 2 and 5 - here just fix the noun’s own ending.
• In Brazil: gender and plural rules are identical; only the pronunciation of the endings differs (recall the reduced European vowels from the reading & pronunciation guide).