Welcome to the grammar unit of the book. For new teachers grammar is the most intimidating language element to teach. Unfortunately, most students over the age of 10- or 11-years-old develop a need to understand why and how something works. Children don’t have such a need, they just accept things the way they are; this is the reason why they are such good learners of languages. Teenagers and adults do have this need. As much as it would make both the students’ and teachers’ lives easier if they didn’t have a need to understand how it works, they do need to know. So you are going to have to learn how to teach them.