Practice the dialog with your friend
Answer the questions that follow, orally.

Lia: Have you finished your work?

Rangga: I haven't. I couldn't finish it due to a blackout. We stayed in darkness for several hours.

Lia: Did you not turn on an emergency lamp?

Rangga: I did, but I couldn't use my computer.

Lia: We have a similar problem.

Rangga: What do you mean? Haven't you finished your work, too?

Lia: I haven't. The blackout occured suddenly while I was doing my work.

Rangga: Why did you not use your laptop computer?

Lia: It is being repaired. Anyway, the worst is I lost my work!

Rangga: Oh no. How could it be?

Lia: I forgot to save my work before the blackout occurred.

Rangga: I am sorry to hear that. You should keep saving any work on computer every fifteen minutes.

Lia: You're right.

What modal auxiliary is used to suggest something?