1) A worksheet explaining the -CAR, -GAR, ZAR spelling changes in the YO form of the preterit.
2) 10 questions using these verbs where student responds in YO form.
3) a worksheet for partners to ask and answer same questions and write down response.in 3rd person.
This exercise emphasizes the fact that the spelling changes only apply to the YO form of the Preterit conjugation of these types of verbs.
It is both a written and oral exercise.