which sentence contains a y stem - changing verb? pierdo el balón de fútbol. el se cayó. me duermo muy tarde.

which sentence contains a y stem - changing verb? pierdo el balón de fútbol. el se cayó. me duermo muy tarde.
Answer
Brief Explanations:
In Spanish, stem - changing verbs have a vowel change in the stem in certain forms. "Perderse" (to lose) in "Pierdo" doesn't have a typical stem - change pattern. "Cayó" from "caerse" (to fall) is a regular preterite form. "Dormirse" (to go to sleep) is a stem - changing verb (o - ue in the first - person singular present form "duermo").
Answer:
Me duermo muy tarde.