• the grammar files series consists of 5 books, for cef levels: a1 - a2 - b1 - b2 - c1• each unit starts by briefly introducing the new grammar point and then students have to practise doing a variety of exercises.• these books can also be used as time fillers; perfect for when teachers have some extra time at the end of a lesson, or want to revise a specific grammar point.• levels b1 and b2 have also been written for students who are planning to take the ielts exam. although grammar is not tested directly on the ielts, it is tested indirectly in the speaking and writing sections of the exam. you can gain or lose points based on your command of english grammar, therefore, it would help to undertake a general review of english grammar while preparing for the ielts.