Spotting the Error is a problem-based workbook on English grammar and usage for advanced learners of English. Each of the over 300 sentences included in the exercises contains at least one error, and the learner's task is to identify, correct, and explain the nature of the errors. The exercises are based on sentences in essays written by university students of English in Sweden. The key provides correct versions of all sentences, and explains the nature of most of the errors. References to Engelsk universitetsgrammatik are given in the workbook. The book's website, www.studentlitteratur.se/spottingtheerror, provides references to several other books (the Longman Student Grammar of Spoken and Written English, Modern engelsk grammatik, the Longman Dictionary of Common Errors, and A University Grammar of English - with a Swedish Perspective), as well as additional material. The main target group of Spotting the Error comprises students taking basic ("A") courses or special-purpose courses in English at Swedish universities. However, this workbook may also be useful for secondary-school students taking advanced courses in English, and for others who are interested in English grammar and usage.