What's the difference between 'boring' and 'bored'?

The rule:

-ing adjectives describe the thing causing the feeling.
-ed adjectives describe the person experiencing the feeling.

• The film is boring. (the film causes boredom)
• I am bored. (I feel boredom)

Never: "I am boring" — unless you mean you are a dull person who bores others. This is a very common learner error.

• Interesting / Interested: "The topic is interesting. She is interested."
• Exciting / Excited: "The news is exciting. I am excited."
• Tiring / Tired: "The work is tiring. I am tired."
• Confusing / Confused: "The instructions are confusing. I am confused."
• Surprising / Surprised: "The result is surprising. I am surprised."

Quick test: Is it the thing or the person? Thing → -ing. Person → -ed.

Tags: grammar, adjectives, common mistakes, -ing vs -ed