"Young Fives" may be old enough for kindergarten, but are they developmentally ready? To address the needs of these children, some schools are offering transitional kindergarten (TK) classes, which promote positive socialization, hands-on learning, and emergent literacy. But there’s also an ample amount of play time. After a year of TK, children either go on to a year of regular kindergarten or on to first grade, depending on their readiness.