Do you know the English idiom Speak of the devil?

Read the conversation below. Can you guess how it is used?

Robert: Kevin called the other day. He was telling me about his new job.

Emily: Speak of the devil. Kevin, how are you?

Kevin: Hi guys. I’m doing fine. How are you doing?

Is it used

a) when you think Kevin is a devil?

b) when a person who is being talked about appears?

c) when someone you don’t like appears?

d) when you shouldn’t talk about someone when they are not there?

The answer is below ↓

 

Answer: b) when a person who is being talked about appears.

In the conversation, Robert was talking about Kevin, when Kevin suddenly appeared.