7. Modal Verbs express ideas such as Possibility, Intention, Obligation and Necessity (More on the use of Modals and similar structures in your Textbook)
9. FORM: Modal (+not) + HAVE + PAST PARTICIPLE Questions: Modal + Subject + Have + Past Participle USES: Certainty, Guess, Regret, Possibility, Ability, … IN THE PAST
10. SOME EXAMPLES: I may have lost my keys (Perhaps I lost them) He must have left (I am quite sure he left) She could have passed last year (She had the chance to pass but she didn’t) Should I have told you before? (Was it a good idea to tell you?)