Say, for example, I'm a drow or a tiefling. I have the darkness spell once a day. However, I'm a warlock with Devil's Sight and I want as many chances to cast darkness as possible. Can I take darkness as a warlock spell as well, or can I only take it once as a racial spell?
Because I can't use slots to cast the racial spell (If you have the ability to cast a spell without a spell slot can you cast that spell using a spell slot?), I can't do that for extra uses. So could I, in that example, take darkness again or am I stuck with only the racial ability?