This book is exclusively meant for learners of English, both at elementary and intermediate level. When they speak English they are bound to make a number of mistakes. Grammarians say that these mistakes can be divided into two groups, i.e, mistakes in system garmmar and mistakes in word grammar. Mistakes in system grammar refers to the wrong use of auxiliary verbs (Might I come in?), wrong use of tense (He said that he is writing last night) etc. Mistakes in word grammar means that the learners use a wrong word (He made suicide) or use a wrong preposition (He is gazing on the poster.) or fail to use a preposition (Please listen me.) etc.