What’s the difference between common and proper nouns?

A common noun is not capitalized, as it names a category of person, place, thing, or concept. Common nouns often require articles (e.g., “a”) or determiners (e.g., “many,” “his”).

In contrast, a proper noun is capitalized and names a specific person, place, thing, or concept. Most common nouns don’t require an article, but some require “the” (e.g., “the Great Lakes”).