How is it used?
The book can be used either in the classroom or as a self-taught instrument. For this reason, at the end of the book are an answer key with all of the answers to the exercises plus Spanish/English and  English/Spanish glossaries with all the necessary vocabulary to understand the exercises.
Each unit can be dealt with in an independent way: teacher or student can solve a specific question without having to follow the book from beginning to end.
Each person can begin the book either at the Contents, where the units are organized by grammar points, or at the Index, where concepts and key words are included in alphabetical order.

A work proposal

To work on new grammar aspects for the student:
Read the theory.
Do the exercises.
Review the exercises with the help of the answer key, highlighting the incorrect answers.
Read the theory again, focusing on finding new information that explains the mistakes made in the exercises.
Do the exercises again and then review them.
Repeat the previous step a few days later.
To work on grammar points that the student already knows:
Do the above-mentioned process starting on the second step. Read the grammar theory only to check the reasons for certain mistakes.
To work on units that contain grammar points and common subjects and that are related to each other through rerference marks:
Remember previous contents necessary for the comprehension of a new unit or units by going back to the units indicated in a reference mark and reading the theory.
Advance and go into more detail in the grammar point or content by going to the unit or units indicated in the reference mark, reading the theory, and doing the exercises.
To do a self-test for each unit, complete the table that appears in the margin of every exercise with the number of correct answers.
To work on basic questions referring to Spanish grammar, two units are included at the back of the book that can be studied at any time, regardless of the itinerary chosen for the book units.