You contact your deity or a divine proxy and ask up to three questions that can be answered with a yes or no. You must ask your questions before the spell ends. You receive a correct answer for each question.
Divine beings aren’t necessarily omniscient, so you might receive “unclear” as an answer if a question pertains to information that lies beyond the deity’s knowledge. In a case where a one-word answer could be misleading or contrary to the deity’s interests, the DM might offer a short phrase as an answer instead.
If you cast the spell two or more times before finishing your next long rest, there is a cumulative 25 percent chance for each casting after the first that you get no answer. The DM makes this roll in secret.
You can find more information on this spell in: PHB.223