It is a matter of great satisfaction to me that the earlier editions of the book got wider acceptance by the teachers and students from all corners of the country. Over the time I received a number of suggestions from many practising teachers. So a revised edition of the book was required and in view of the present book has been prepared. The language of the book has also been further simplified and at the end of every chapter self-explantory questions have been reframed. I think, in its present form, the book has received a higher utility scale. I express my deep sense of gratitude to the teachers who have prescribed my book and who have taken the trouble to send me their valuable suggestions. I hope to get their cooperation in future also. I sincerely thank Dr. Vijay Mishra of Varanasi, for going through the book and providing his valuable suggestions.