Indefinite Article
Spanish: Cambridge International GCSE, topic 11.1.3
Nouns
The indefinite article is used to describe when there isn't an exact number of the thing. There are four forms: masculine singular and plural and feminine singular and plural.

Masculine singular
- If a noun is singular and masculine it uses the indefinite article of 'un'.
- Most masculine singular nouns will end in an 'o'.
- Un perro (🐕) - a dog.
- Un niño - a child.
- Un casamiento - a wedding.

Masculine plural
- If a noun is plural and masculine it uses the indefinite article of 'unos'.
- Most masculine plural nouns will end in 'os'.
- Unos gatos (🐈) - some cats.
- Unos casamientos - some weddings.
- Unos compañeros - some friends.

Feminine singular
- If a noun is singular and feminine it uses the indefinite article of 'una'.
- Most feminine singular nouns will end in 'a'.
- Una mesa - a table.
- Una fecha - a date.
- Una semana - a week.

Feminine plural
- If a noun is plural and feminine it uses the definite article of 'unas'.
- Most feminine plural nouns will end in'as'.
- Unas casas - some houses.
- Unas cajas - some boxes.
- Unas mentiras - some lies.
Test yourself on Indefinite Article
What is the plural of 'Un perro' in Spanish?