The study of verbal periphrasis has a long tradition, but this does not make it easier for the philologist or easier for the student of Spanish. Because what is actually a verbal periphrase? In addition, generalizations can be made about some uses and functions of periphrases, but on other occasions they are uses and individual facts that we simply must learn as such. This manual offers a defining and key guide to all the points that can be problematic in a subject as complicated as verbal periphrasis in Spanish.