The book "Basics of Grammar in Practical Application" by Raymond Murphy

Grammar in Use is the world's best-selling grammar series for learners of English. Essential Grammar in Use Fourth edition is a self-study reference and practice book for elementary-level learners (A1-B1), used by millions of people around the world. With clear examples and easy-to-follow exercises, it is perfect for independent study, covering all the areas of grammar you will need at this level. This edition includes an eBook, for use on tablet devices and desktop and laptop computers. The eBook has the same grammar explanations and exercises found in the printed book, plus other great features such as integrated audio for all of the example sentences and an easy-to-use answer key.