Why "bored"

[YOSHITAKEHORI]

I found the following sentence in Cambridge English Readers.
But I don't understand why a word "bored" can be used instead of
boring. Could anyone tell me?
Qot
I thought for a moment that she was trying to catch my eye.
But then she turned away with a bored expression on her face.
Unqot
We can say "This is a boring job." but why "with a bored expression"

[Ouisch]

"Boring" is an active voice adjective. "Bored" in your example is describing the expression on her face, which needs to be in the passive voice. We're not saying that her face is boring, we're saying that she wore an expression that indicated that she felt bored.

I hope that made some sense.

[rewboss]

In other words:

If something is boring, it means that it causes boredom. If something (or, more usually, someone) is bored, it means that it is experiencing the effects of boredom.

A "boring expression" would be an expression that bores you. You'd look at a person's face and think: "That face just doesn't interest me. It makes me want to go to sleep."

A "bored expression" is an expression that shows that the person is experiencing boredom. You'd look at a bored expression and think: "That person is about to fall asleep from boredom."

There are some other -ing/-ed pairs like this. So "interesting" describes something that interests you; "interested" describes a person who has an interest in something.

"That girl over there is very interesting to me -- I'd like to go and talk to her. But she doesn't seem interested in me; she's more interested in her book. It must be a very interesting book."

[YOSHITAKEHORI]

Ouisch san
rewboss san
Thank you for your replies. I have not 100% understood yet. But thanks to
your advise, I could imagine it.
Is this sentence correct? (gramatically)
''He came back in a hurry with a excited expression. Because the game he watched in a studium was very exciting."

[rewboss]

That's right, except it should be "an excited expression". But I think you've got the basic idea. :)

[river]

Adjectives ending in "-ing" usually describe the effect that something has on someone's feelings {That teacher is so boring}. Most adjectives ending in "-ed" describe people's feelings {I'm bored in this town. There's nothing to do}.

[YOSHITAKEHORI]

rewboss san
river san
Thank you for your replies again.
This is the final question, but is this sentence correct?
"I felt bored that day since I had to talk with a boring person all day long."
This sentence means that "this person didn't feel bored , but he made me feel bored."
Thank you in advance.

[Casiopea]

It's correct.

another example
Sam is boring. <present participle; describes how people view Sam>
Sam is bored. <past participle; describes Sam's state>
Sam is boring us to tears. <present continuous verb: to bore someone; to tears > when you're bored, you yawn and that can bring your eyes to water, to tear up, to shed tears.)

Note that, the Japanese title of respect "san" isn't required in English. Just the person's name will do.

[YOSHITAKEHORI]

Casiopea

Thank you for your advice with three examples which is really
useful for me. Now thanks to the explanations by all your members,
I got it.

[Casiopea]

You're most welcome.

Grammar Help
...three examples which are really, not which is.