what is the difference between "algún" and "alguno"

Question

What is the difference between "algún" and "alguno"? Is one an adjective and the other a pronoun?

Answer 1

The are the exact same word. algún is just an apocopation (shortened) form of alguno.

Alguno becomes algún when used before a masculine, singular noun.

de + el=del

a + el = al

primero, tercero=primer, tercer

ningún

are all common forms of apocopation.

Algún would always be an adjective, but alguno could either be an adjective (following a masculine noun) or a pronoun.

Here is a link on the apocopation of adjectives since that is what you asked about.

apocopation

Answer 2

In "algún", you have to add a subject. "alguno" is indeed a subject.

"¿hay algún ingeniero ahí?" "is any engineer there?" algún + subject (engineer)

"There are some engineers" "any of them that could help me?" "¿Alguno que me ayude?" - there is no subject; the subject was in the last sentence (engineer)

"algún" = "any" "alguno" = "any of them" "any of those" "any of these"