How do you know you have the gift of tongue?

How do you know you have the gift of a tongue?

According to my experience, a tongue is really a spiritual gift from God. When you pray, the Holy Spirit comes upon you and you speak out one kind of another language to communicate with God. I gained a tongue one time pray in the retreat of Eve. I know that is a tongue because I realized that it was my soul speaking another language that I don’t know.But I felt smooth.