Practical English Usage is a dictionary of problem points in the language for foreigner, learner´ s and their teachers. It answers the learner´s question. "Is this right or wrong, and why?" and the teacher´ s question. "How can I explain this to may 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, pronunciation and spelling