Stem-changing verbs in the subjunctive: -IR verbs that have the change e > ie or e > i in the present indicative have the same changes in the present subjunctive. However, unlike the present indicative, these verbs also have the e > i stem change in the nosotros/nosotras and vosotros/vosotras forms in the present subjunctive. Dormir and morir have the o > ue change in the present subjunctive, but they also have the o > u stem change in the nosotros/nosotras and vosotros/vosotras forms.
-AR and -ER stem-changing verbs work like the present indicative: pensar - piense, pienses, piense, pensemos, penséis, piensen