What is the Indefinite Article and the Plural Forms of Nouns and Adjectives in Portuguese Grammar?

The Definite Article

The definite article (o artigo definido) in Portuguese has a masculine and a feminine form (there are no neuter forms of nouns). The singular masculine (m) article is “o”, and the feminine (f) singular article is “a.” Plural forms are made by appending an “s” to the respective singular forms as shown below:

  • o gato [m, singular] (the cat)
  • os gatos [m, plural] (the cats)
  • a caneta [f, singular] (the pen)
  • as canetas [f, plural] (the pens)

Example: O gato brinca com as canetas (the cat plays with the pens).

Now you are ready to learn the plural forms of nouns (substantives) and adjectives. For the sake of conciseness, the term “word” acts as a placeholder for a noun or adjective throughout the rest of this article.

Plural Forms of Nouns and Adjectives

In Portuguese, plural forms of nouns and adjectives (o plural dos substantives e adjectivos) are built according to these rules:

In general, especially if the word has an ending vowel then append “s”:

  • a menina (the young girl) –> as meninas
  • o menino (the young boy) –> os meninos
  • alemã (German) –> alemãs

Examples: A menina e os meninos gostam de canetas alemãs (The girl and the boys like German pens).

Stressed aõ usually becomes ões:

  • a lição (the lesson)–> as lições
  • But: a mão –> as mãos

Examples: As lições duram 45 minutos (the lessons are three quarter of an hour). Minhas mãos são pequenas (my hands are small).

If the word ends in r, s, or z then append “es”:

  • o elevador (elevator) –> os elevadores
  • o Portuguese (Portuguese, masculine) –> os Portugueses
  • a vez (time(s)) –> as vezes

Example: Às vezes e quando (sometimes) os Portugueses usam o elevador (The Portuguese [people] sometimes use the elevator).

If the word ends in m then change its ending to ns:

  • bom (good) –> bons

Example: Os carros são muito bons (the cars are very good).

If the word ends in al the plural becomes ais:

  • qual (which)? –> quais?

Example: Quais são as coisas mais importantes na vida (which are the most important things in life)?

If the word ends in ol the plural becomes óis:

  • o anzol (fishhook) –> anzóis

If the word ends in ul the plural becomes uis:

  • azul (blue) –> azuis

Example: Canetas azuis (blue pens).

If the word ends in el the plural becomes éis:

  • o anel (ring) –> os anéis

If the word’s ending is unstressed il or el the plural becomes eis:

  • amável (lovely) –> amáveis
  • fácil (easy) –> fáceis

Example: As lições são fáceis e a professora é amável (the lessons are easy and the teacher is lovely).

If the word’s ending is unstressed is, es, as or ax the adjective or noun remains unchanged:

  • o lápis (pencil) –> os llápis
  • o tórax (chest) –> os tórax
  • pires (tawdrily)
  • o atlas (atlas) –> os atlas

Example: Os alunos escrevem com canetas ou lápis (the pupils write with pens or pencils).

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