English Grammar in Use: A Self-Study Reference and Practice Book for Intermediate Learners of English - with Answers

English Grammar in Use: A Self-Study Reference and Practice Book for Intermediate Learners of English - with Answers

Essential Grammar in Use with Answers: A Self-Study Reference and Practice Book for Elementary Learners of English

Practical English Usage, 4th Edition Paperback with Online Access: Michael Swan's guide to problems in English