This is a reference and practice book of words and structures often confused or misused by learners. It is aimed at intermediate students and above in the upper secondary to adult age range. The book contains a reference section of 200 pages which has examples and explanations of 5000 words often confused or misused. There is a test yourself section of approximately 100 pages containing practice exercises, graded according to difficulty and organized according to topics, functions or grammar. There is also a key to the exerciese and a detailed index. The common errors dealt with include: words confused due to native language interference eg benzine, petrol; confusable words within English itself eg rob/steal/burgle; grammatical structures confused due to L1 interference eg it is/ it has; grammatical structures often used wrongly eg must/had to; miscellaneous things that often cause difficulty eg get, enjoy. The test yourself section makes the book particularly suitable for students working for FCE, CAE and Proficiency exams. Teachers should also find it useful in helping them to answer awkward "on the spot" questions. The book has been piloted in a number of countries representing all the major language groups to ensure that entries included do in fact present problems for the majority of students.