Verbs ending in -ir that undergo stem changes in the present tense also under go stem changes in the preterite. These verbs have a stem change in the second person formal singular (usted), third person singular (él, ella) and third and second person plural (ellos, ellas and ustedes) forms.
Nosotros vamos a hacer la cama todos los días.
Cool, goodluck on your assignment bud. :)
