-НУ-

Verbs with this suffix are treated the same as 2C verbs: stress is default in the infinitive and past-tense forms, but since the suffix -ну- mutates to -н- when conjugated stress falls on the ending in the present/future:

default (stress the first vowel after the root):

вернуть, вернул, вернула

верну, вернёшь, вернут

Forms that are stressed on the root will be marked in the text:

дунуть, дуну

перепрыгнуть