What are stem changing verbs, and how do I form them?

Stem changing verbs in Spanish can be a real pain to conjugate if you don’t know the rules to follow. A stem changing, or ‘boot’ verb, is one which changes its spelling for certain persons in the present tense. For example: Empezar – To Start (e -> ie) Empiezo         Empezamos Empiezas               Empezáis Empieza                 Empiezan In this example, the ‘e’ in the middle of the infinitive form of the verb becomes an ‘ie’ in the first, second, and third person forms of the present tense. These are sometimes called boot verbs as, if you drew a circle around the forms of the verb that change stem, it forms a boot shape. Stem changing verbs are very common in Spanish, and so it is important to be able to recognise them, and remember how to form them. Here are some examples of common stem changing verbs, see if you can conjugate them into the present tense in all 6 forms. Entender – To Understand (e -> ie) Cerrar – To Close (e -> ie) Comenzar – To Start (e -> ie) Mentir – To Lie (e -> ie) Perder – To Lose (e -> ie) Pensar – To Think (e -> ie) Poder – To Be Able To (o -> ue)