Modal verbs of deduction: Must, might, could, can’t — Exercise 3
Fill in the blanks in the conversations with must, might, might not, or can't.
Emma: Did you hear about what happened in the office last night?
Liam: Yes! The alarm went off at 2 a.m. Someone entered the building.
Emma: I’m not sure. The security guard said all the doors were locked. So no one broken in.
Liam: That’s strange. Then the alarm gone off by mistake.
Emma: Possibly. But the lights in Mr. Harris’s office were on. He forgotten to turn them off.
Liam: I doubt it. He’s very careful. He left them on.
Emma: Well, someone been inside because some files are missing.
Liam: The cleaning staff moved the files.
Emma: No, they finished work at 8 p.m. They been there at 2 a.m.
Liam: True. Then it be something serious.
Emma: Or it just be a technical problem with the alarm system.
Liam: But the window in the meeting room was open. Someone have come in that way.
Emma: That’s possible, but the window is very small. A person fit through it.
Liam: Then the manager know more than he is telling us.
Emma: He looked calm this morning. He think it’s a big problem.
Liam: Or he worried and just hiding it well.