Practical English Usage, 4th edition, 4th edition. — Oxford University Press, 2016 (PDF).
Completely revised and updated to reflect changes in language use.
NEW Organisation into two easy-to-use parts, making it quicker to find the information you want. Part 1 is a complete topic-by-topic student’s grammar, with section introductions highlighting common mistakes. Part 2 is a guide to key vocabulary topics, including an A-Z list of common word problems.
NEW Also available online, including 87 diagnostic tests.