This book is based on a study of referees' reports and letters from journal editors on reasons why papers written by non-native researchers are rejected due to problems with English (long sentences, redundancy, poor structure etc). It draws on English-related errors from around 5000 papers written by non-native authors, around 3000 emails, 500 abstracts by PhD students, and over 1000 hours of teaching researchers how to write and present research papers.