Nouns and their Pronouns
Which is correct? un libro, una libro, unos libro, or unas libro
2 Answers
Hi janltoy, welcome to the forum!
Firstly, these are not pronouns. These are indefinite articles (un, una, unas, unos). Additionally, there are also definite articles (el, la, los, las). The difference between the two sets is that indefinite mean "a" or "an" (a book, some books) and definite mean "the" (the book, the books).
There are two qualities you need to pay attention to when deciding what is the appropriate article to use. Is it feminine or masculine? Is it singular or plural?
"Libro" is a masculine noun. It is also singular in this instance because it doesn't have an 's' attached to the end.
So in this case, since you are only given indefinite articles as choices, it is un libro.
Libro is a masculine noun, so it would be un libro/ unos libros.