TEST C. MATCHING TYPE. Match the given statement to its appropriate answer. Write the letter of the correct answer in your notebook. 11. expresses commitment or duty. Modals used in expressing obligation include have to (has to) and must. 12. 13. Modals are auxiliary or is the act of disallowing or prohibiting someone in performing or doing something. Modals showing prohibition include can't and must not/mustn't. 14. is an act of giving consent or authorization. In stating permission, modals to be used include can, could and may. 15. expresses the absence of commitment or duty as one may do it or not. Don't (doesn't) have to is used to express no obligation. a. No obligation b. Helping verbs c. Permission d. Obligation e. Prohibition​