Research on corpora from the view point of language teaching textbooks has enabled researchers to examine the language to which learners are exposed to in order to develop more effective pedagogical materials for EFL/ESL learners. This has been done by many researchers comparing a textbook corpus with reference corpora or real-language corpora. However, all of these studies unanimously show that there is a lack of fit between grammar and textbook descriptions of the target language and real language use which lead us to believe that the language contained in textbooks is usually based on intuition and not on actual and attested use. To date, the focus of most pedagogic corpus-based research has been either on international type of textbooks, or on national textbooks mainly in EFL contexts. Surprisingly, however, English for General Purposes in ESL contexts has been the exception to this rule. Aimed at filling the existing gap by using a pedagogic corpus consisting of ESL Malaysian English language textbooks, this book tries to provide ample information about some of the most important features of the real language in use that went unnoticed in Malaysian English Language textbooks.