This is the 821st most frequent Portuguese word.
alguns
"Some."
Here, 'alguns' refers to an unspecified number of 'amigos,' indicating a portion of a larger group.
Eu convidei alguns amigos para a festa.
I invited some friends to the party.
In this context, 'alguns' refers to an indefinite group of people, indicating the standpoint of an undefined subset of individuals.
Alguns acreditam que o projeto terá sucesso.
Some believe that the project will succeed.
In this sentence, 'alguns' specifies an indefinite quantity of 'livros,' meaning there are books on the table, but not all or a specific number.