This unique reference guide addresses problem points in the language as encountered by learners and their teachers. It gives information and advice that is practical, clear, reliable, and easy to find. Most of the book is about grammar, but it also covers selected points of vocabulary, idioms, style, pronunciation, and spelling. Practical English Usage has sold over 2 million copies worldwide. Now revised and updated for the fourth edition, it answers the questions that teachers and learners ask about English grammar and vocabulary with clear, corpus-informed explanations and examples.