Besides the animate nouns, there is no strict rule for the gender. It is meaningless to say that, in Portuguese, a chair (cadeira) is feminine or a book (livro) is masculine. Compared to English, however, is a good feature of languages like Portuguse the more specific difference between a male friend (amigo) or a female friend (amiga).
The normal ending are -o for masculine and -a for feminine. This is not a general rule, however; actually, few nouns follow it.
Due to its meaning or formation, the noun can be divided in several groups.
Concrete and abstract nouns
A concrete noun refers to things that have independent existence. They can be real or not real, material or not material.
- água (water)
- Brasil (Brazil)
- círculo (circle)
- galinha (chicken)
- João (John)
- professor (teacher)
- repolho (cabbage)
A abstract noun refers to qualities, actions or states, independently of the things to which they are related.
- beleza (beauty)
- calor (heat)
- vida (life)
- encontro (meeting)
- tamanho (size)
Sometimes a noun can be both, depending on the context.
Common, proper, and collective nouns
A noun that refers to a specie is classified as common.
- arquivo (file)
- bananeira (banana tree)
- caixa (box)
- pessoa (person)
- vinho (wine)
A noun that refers to an individual being is classified as proper.
A noun that refer to a collectivity is classified as collective
- arquipélago (archipelago) - of islands
- assembléia (assembly) - of deputies
- exército (army) - of soldiers