Adjectives that end with
-ed talk about one's own feelings, whereas adjectives that end with
-ing talk about a person, a thing or a situation that causes one's feelings.
For example:
The movie was boring (so I felt bored).
This book is so interesting (so I am interested in the book).
My boyfriend has a very annoying habit (so I am annoyed).
English usage can be confusing (so a lot of students are confused).
My husband's job promotion was surprising (so we were very surprised).
The baseball game between the Giants and the Tigers was exciting (so the fans were excited).