After reviewing the information on stem-changing verbs, explain what a stem-changing verb is and choose one of the major types of stem-changing verbs and explain how to conjugate it.

Stem- changing verbs are also called stem-changer because it's a  different kind of predictable verb conjugation in which the stem of the verb changes and the endings are normal. The ending is what is irregular.  For the verbs presented so far, The stem of a verb is what is left when you remove the infinitive ending (‐ar, ‐er, or ‐ir).  Because the stem of the verb changes, these verbs are called stem‐changing verbs, or stem‐changers.

The hardest part about stem‐changers is that one have to memorize the verbs in which stem changes occur. Once you memorize the type of stem change a verb undergoes, the actual patterns of the stem‐changing verbs are quite simple; because all the conjugation endings are regular, conjugating these verbs is easy.

         e>ie stem-changers

The most common stem change is e>ie. That means the stressed letter e in the stem of the verb will change to ie in certain forms of the verb. If a verb has two e's in the stem, it will always be the second e that undergoes a stem change.The verb cerrar is typical of an ‐ar verb with an e>ie stem change.