Basic Grammar in Use - Murphy Raymond, Smalzer William.

Basic Grammar in Use Fourth Edition is an American English, self-study reference and practice book for elementary level learners (A1-B1). It is a book that has been used by millions of people around the world to improve their English. With simple explanations, clear examples and easy to understand exercises, it is perfect for students who are studying on their own, but can also be used in the classroom.