Intended for researchers, pre- and post-graduate students and foreign language teachers interested in corpus linguistics, this book is a valuable and original source of documentation for the tagger EARS: a system of tags for annotation of written errors at spelling, punctuation, word, phrase, clause and lexis levels in English learner corpora. This manual gives a thorough description of the tagger, and a fully exemplified account of the guidelines for its application. This publication finds its place among other databases, for example, LOB, BNC, ICLE, or software releases, like MicroConc or WorthSmith Tools, with which it shares their applicability in language corpus research. However, this one is distinctive in that it is specific to learner corpus research, where few specific tools and detailed manuals have been made available to date.