Spanish has definite and indefinite articles like English, so at least the concept is not unknown. However, even then, the correct usage is sometimes really arb

Spanish has definite and indefinite articles like English, so at least the concept is not unknown. However, even then, the correct usage is sometimes really arbitrary and varies across languages, e.g. why is it typically "mankind" and not "the mankind" (by contrast, in German it's "die Menschheit", with an article)?