A-levels have been modular since 2000, with teenagers taking AS-level exams after their first year and "A2" exams at the end of the course. Pupils will take the reformed AS-levels for the first time this summer and sit their final A2 exams, in which the A* will be introduced, next year. In a letter to schools, Ofqual chair Kathleen Tattersall said the new exams "bring unique challenges" for candidates and their teachers with unfamiliar types of questions.