Articles and quantifiers are different parts of speech in most grammars. Articles are specifically different in having no independent meaning, more similar to p

Articles and quantifiers are different parts of speech in most grammars. Articles are specifically different in having no independent meaning, more similar to prepositions than to adjectives (which some is classified as in its use as a quantifier that we were discussing here). English just doesn't have an indefinite plural article. This is not actually that uncommon - German has the same property, for example.