Rachel: Have you seen David today? Try checking his desk—he might have left his keys here.
Mark: I looked earlier, but they weren't there. Economists warn that travel expenses could rise even further next year, so he may have decided to take the bus today instead of driving.
Rachel: That makes sense. Honestly, you could at least let me know when you're leaving for lunch! He might have told me he was going to be late, too.
Mark: Sorry about that! Well, I might as well finish this report now—I've got nothing else to do while I wait for him.
Rachel: True. By the way, may I ask a personal question? Can I borrow your laptop charger for an hour?
Mark: Of course, you can borrow it. But you can't take it out of the office!
Rachel: Deal. Oh, look at that photo on your desk—is that your grandfather?
Mark: Yes! My late grandfather could play the banjo, but he couldn't sing very well.
Rachel: That’s awesome. Did you get to leave early yesterday to pick up your new instrument?
Mark: Yes, I was allowed to leave work early yesterday to go and meet the seller at the music shop. I managed to buy a vintage acoustic guitar last night, but I couldn't persuade the owner to give me a discount!
Rachel: Well, there’s a strong possibility that you’ll get better at bargaining next time.
Modal Verb Breakdown in the Dialogue:
Present/Past Possibility: might have left, could rise, may have decided
Annoyance: could at least let me know, might have told me
No Better Alternative: might as well finish
Permission & Requests: May I ask, Can I borrow, you can borrow, you can't take
General Past Ability: could play, couldn't sing
Specific Past Permission (Single Occasion): was allowed to leave
Specific Past Achievement (Single Occasion): managed to buy
Negative Specific Past Action: couldn't persuade
Future Possibility Phrase: strong possibility that...
Work in pairs to write a similar dialogue using modal verbs.