'Excited' describes how YOU feel; 'exciting' describes what the thing itself is like, the cause of that feeling.
"Excited" (the -ed ending) describes a person's feeling: you are excited about something. It's used for people, animals, anything capable of feeling emotions.
I'm so excited about the trip next week, I can't stop thinking about it.
The kids were excited to open their presents on Christmas morning.
She got excited when she heard she got the job.
"Exciting" (the -ing ending) describes the quality of the thing that causes that emotion: the movie, the trip, the news is what's exciting.
That was such an exciting game, I was on the edge of my seat the whole time.
Moving to a new city can be both scary and exciting.
We have some exciting news to share with the team today.
Common mistake
"I am exciting about the trip" is a classic mistake: it sounds like YOU are the exciting one (as if you're saying "I am thrilling"), not that you feel the emotion. The correct version is "I am excited about the trip".
Trick to remember it
Same pattern as "bored/boring" and "interested/interesting": the person who feels something ends in "-ED" (excitED = you feel excitement), and the thing that causes the feeling ends in "-ING" (excitING = the thing causes excitement).
Quick rule
Talking about how a person feels? "-ED" (excited). Talking about what the thing itself is like, the cause? "-ING" (exciting).
Did you know?
This "-ed" (who feels) / "-ing" (what causes) pattern exists because both forms are actually participles of the verb "excite": the past participle (excited) is used as a passive adjective (someone was excited by something else), and the present participle (exciting) is used as an active adjective (something is actively causing the excitement). It's the same grammatical logic behind dozens of English pairs: tired/tiring, confused/confusing, annoyed/annoying, frustrated/frustrating.
Exercise 1 · Pick the right one
We're really _____ about the concert this weekend, we've been waiting months for it.
Exercise 2 · Pick the right one
The new roller coaster is the most _____ ride in the whole park.
Exercise 3 · Form the word
One describes how you feel, the other describes what causes that feeling.
'Exhausted' describes how YOU feel (worn out); 'exhausting' describes what causes that tiredness.
"Interested" describes the subject who feels the interest; "interesting" describes the object that causes it.
'A' is used before consonant sounds; 'an' is used before vowel sounds.
Bryan López
Founder of SpeakUP Academy