Practical English Usage is a dictionary of problem points in the language for foreign learners and their teachers. It asnwers the learner's question, 'Is this right or wrong, and why?' and the teacher's question, 'How can I explain this to my classes?' 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, idiom, style, pronounciation, and spelling.