Given that this is the fourth edition of Practical English Usage (henceforward: PEU), my first instinct while preparing to write this review was to go and search for the ELTJ reviews of the former three. To my amazement, I have discovered that there are none. The lack, to my mind at least, is not a case of a major oversight, but rather a reflection of the unique status of PEU as one of the few instant classics in our field, the ultimate reference book for a great many professionals, and an all-time favourite title on their grammar shelf. The main marketing slogan, featured on the PEU back cover, is that it is ‘your indispensable guide to problems in English’—and this must be the first time in ELT publishing history where this sort of pronouncement actually underplays the value of a book in the eyes of several generations of its users. A little informal survey among my social media contacts, asking for their memories of using editions 1–3 of PEU (both as teachers and, possibly, as former learners of English), yielded comments like ‘my last resort, my final answer, my best friend’, ‘the best grammar reference book for non-linguists’, a book which ‘all students of English should consult during the course of their studies on a daily basis’, and last but emphatically not least, ‘my English grammar “Bible”’. In view of such user attitudes, it is easy to see why there has been little interest to date in a critical evaluation of Michael Swan’s magnum opus. Over its 38 years of being in print, PEU has gained a sort of religious cult status, enjoying an almost mythical reputation for containing all the answers to one’s English grammar problems, as well as for its legendary ease of retrieval of just the information one needs. Unsurprisingly, PEU is one of the greatest success stories in the history of ELT publishing, having sold over 2 million copies worldwide (according to the publisher’s blurb).