Quick answer
claro
Natural: of course / sure
Literal: “clear”
How it is used
Claro que sí.Of course. / Absolutely.
Claro, no hay problema.Sure, no problem.
—¿Vienes? —Claro.—Are you coming? —Of course.
Claro que no.Of course not.
Where it is said
You hear it everywhere in the Spanish-speaking world; in Spain people often swap in <b>vale</b> or <b>por supuesto</b> for the same job.
A mini dialogue
— ¿Me puedes ayudar un momento?— Can you help me for a second?
— Claro, dime.— Of course, tell me.
Watch out
claro
Learners often use it as the adjective “clear” about ideas, but on its own claro is agreement, not a description.
Check yourself
Which reply means “of course not”?