Samantha: I'm trying to decide what movie to watch tonight. Can you suggest any old movies? I want something romantic.
Rebecca: Have you seen Casablanca?
Samantha: Yeah, I cried at the end.
Rebecca: What about Gone With the Wind?
Samantha: Yep - but that's old. Maybe something a little newer.
Rebecca: I assume you've already seen Titanic?
Samantha: Actually, I haven't.
Rebecca: Really? You have to watch Titanic! It's one of the must-see movies of the 90s! I thought everyone had already seen it. How could you have missed it?
Samantha: Uh, I was born in the 90s.
Meaning: "Must-see" is an adjective that means something should be seen by everyone. This idiom is usually used for movies and plays. In the example, Rebecca says that Titanic is a must-see movie, which means she thinks everyone should see Titanic.
Here is another example:
Stephanie: I saw the musical The Book of Mormon last night on Broadway.
Harry: How was it?
Stephanie: It was just OK. I had heard so many good things, I thought I was going to love it, but I wouldn't say it's a must-see.
Harry: That's too bad. I was excited to see it.
Meaning: In this case, Stephanie said that The Book of Mormon wasn't a must-see, so she doesn't think everyone should see it. notice that even when used as a noun, there is a hyphen between the two words.
This idiom is from the upcoming edition of LSI's book "Reading Horizons," which will be used in the Level 6 Reading classes. For more information, please visit http://www.languagesystems.com/