Read the Learn this! box. Underline the past modal verbs in the dialogue in exercise 1.
Freya: I can't find my camera, Archie.
Archie: There it is. It's under your bag. Why do you have to bring it to class?
Freya: I must take it to my photography class today. By the way, I didn't understand that email you sent me yesterday.
Archie: I didn't send any emails yesterday.
Freya: Well, you might have sent it earlier. But I got it yesterday.
Archie: I can't have sent you an email. My phone hasn't been working for a week.
Freya: Somebody must have used your account. The email had a link to a competition, but when I clicked on it, nothing happened.
Archie: Oh no! You shouldn't have clicked on the link. You've possibly downloaded some malware onto your phone.
Freya: That's terrible! You should have warned me earlier.
Archie: I didn't know! Anyway, you might not have downloaded anything. It's possible that you were lucky. You just need to wait and see.
Freya: Anyway, you need to warn your other friends. That email could have gone to everybody in your address book!
