Indefinite Articles in Portuguese

Overview

Indefinite Articles (Artigos Indefinidos) are a beginner (CEFR A1) concept covering the Portuguese equivalents of English "a/an" and "some." Portuguese has four indefinite article forms: um (masculine singular), uma (feminine singular), uns (masculine plural), and umas (feminine plural).

Unlike English, Portuguese has plural indefinite articles (uns/umas) meaning "some" or "a few." Also notable is that Portuguese often omits the indefinite article with professions after ser: Sou médico (I am a doctor) rather than Sou um médico.

Indefinite articles follow the same gender and number agreement rules as definite articles and must match the noun they accompany.

How It Works

The four indefinite articles in Portuguese:

	Singular	Plural
Masculine	um (a/an)	uns (some)
Feminine	uma (a/an)	umas (some)

Standard usage:

• um livro — a book
• uma casa — a house
• uns amigos — some friends
• umas flores — some flowers

When to omit the indefinite article:

1. After ser with professions: Sou professor. (I'm a teacher.)
2. After ser with nationality: Sou português. (I'm Portuguese.)
3. After sem (without): Saiu sem chapéu. (He left without a hat.)
4. After ter in negation: Não tenho carro. (I don't have a car.)
5. With meio/meia, certo/certa, outro/outra: certo dia (a certain day), outro livro (another book)

When the article is required:

• To emphasize: Sou um bom professor. (I'm a good teacher.) — the adjective triggers the article
• For unspecified quantity: Comprei uns livros. (I bought some books.)

Examples in Context

Portuguese	English	Note
um livro	a book	masculine singular
uma casa	a house	feminine singular
uns amigos	some friends	masculine plural
umas flores	some flowers	feminine plural
Sou médico.	I'm a doctor.	no article with profession
Sou um bom médico.	I'm a good doctor.	article with modified profession
Comprei um carro.	I bought a car.	standard usage
Quero uma água, por favor.	I'd like a water, please.	polite request
Há uns dez minutos.	About ten minutes ago.	approximate quantity
Não tenho carro.	I don't have a car.	omitted after ter + negation

Common Mistakes

Using indefinite articles with unmodified professions

• Wrong: Sou um médico.
• Right: Sou médico.
• Why: After ser with professions, the indefinite article is omitted unless the noun is modified by an adjective (Sou um bom médico).

Forgetting the plural forms

• Wrong: Comprei livros. (when you mean "some books")
• Right: Comprei uns livros.
• Why: Portuguese has plural indefinite articles that convey "some" or "a few" — a feature English lacks.

Using um/uma with outro/outra

• Wrong: um outro dia
• Right: outro dia
• Why: In Portuguese, outro (another) does not take an indefinite article, unlike English "another" (an + other).

Confusing um (article) with um (number)

• Wrong: Assuming um café always means "one coffee"
• Right: Um café, por favor. usually means "a coffee, please."
• Why: Context determines whether um/uma is an article or the number one. For emphasis on the number, stress the word or add só (only): Só um café.

Usage Notes

Indefinite article usage is largely consistent between Brazilian and European Portuguese. The main variation is in casual speech, where both variants may omit indefinite articles more freely than in formal writing.

In expressions of approximate quantity, uns/umas is used with numbers: uns vinte pessoas (about twenty people). This usage is informal and common in both variants.

Practice Tips

1. Memorize the set of words that do not take indefinite articles (outro, certo, meio, tal) and practice using them without the article.
2. Practice the profession pattern: say Sou estudante, Sou professor/a, Sou engenheiro/a without articles.
3. When learning new vocabulary, practice using each noun with both its definite and indefinite articles to reinforce gender patterns.

Related Concepts

• Prerequisite: Gender of Nouns — provides the foundational knowledge needed for indefinite articles