This is something I was just thinking about. In English, we seem to rely mostly on articles to tell proper nouns and common nouns apart. Proper nouns are always singular, and lack an article. While common nouns can only lack an article in the indefinite plural.
I was thinking of this because of, well, superheros. Many have common nouns for names. And not all of them are even combinations of words like Batman or Superman. What about Robin, Raven, and Cyborg? If a language lacked articles, then the word 'robin' could just as easily be interpreted as 'a robin' or 'the robin' as the name of a person.
I'm aware that some languages do treat proper nouns differently. Tagalog for instance uses an entirely separate set of prepositions for them (all noun clauses in Tagalog require a preposition, also they only have 3, barring the different forms they can have of course for proper nouns and plural nouns and groups of proper nouns).
I've also read that Russian requires proper nouns in the accusative case to take the genitive ending (normally the accusative ending is identical to the nominative). Spanish also requires proper nouns to take a 'personal a' as a preposition when used as a direct object. Of course, Spanish has articles so its kinda moot.
What other ways do languages have to avoid getting common nouns confused with proper nouns? Do they just avoid using common nouns as names (at least ones that aren't unusual compounds)?
And note that I'm referring to spoken speech. Many languages written with the Latin alphabet capitalize proper nouns, but that doesn't help when hearing the name spoken, obviously.
I want to know this for a conlang. I was thinking of having my conlang lack articles, but if I do that, then it would create an ambiguity in a lot of places when it comes to proper nouns. Maybe I should just have articles, or in general some kind of way of marking definiteness? Yes, I'm aware not all languages use free-standing particles to mark definiteness like we do.