Book excerpt: Hi, my name is Bertha Estela and my passion is teaching. I hold a BA from the BUAP in the teaching of English,and a Masters in the teaching of Spanish as a 2nd.language, from the University of the Americas, Puebla. I have been teaching English at all levels, from Basic, all the way to the preparation for the TOEFL for over forty years, at different places, such as: The American School in Puebla, the University of the Americas; and the BUAP, and, of course at - English/Español Training Center, Consequently, I ended up opening a bilingual school to teach both languages. On doing this, I realized that none of the books that were in the market at that time - drilled the Know How of the structures that do not transfer from one language to the other Therefore , I wrote my own five-level Series Español Fácil, Editorial Trillas, which has been a real hit and another series of five books "Let's Walk the Walk" which were only for internal use at E.T.C, my school. But now, being retired, and terribly excited with the option of buying books online, I have written two workbooks that cover the above mentioned structures in depth. I am positive that they will prove to be an excellent source to clarify structures and drills to help students understand and master the pitfalls that any foreign student learning my wonderful language - Spanish, will have to surpass. Trust my word and, if you have any doubt, contact me at [email protected] without any cost. I will be delighted to help you out.