An adjective that ends in -ING is used to describe: the characteristic of a person, a thing or a situation.
An adjective that ends in -ED is used to describe: a feeling (or how a person feels) or an emotion.
Compare the difference:
My girlfriend is bored. – (My girlfriend feels bored)
My girlfriend is boring. – (My girlfriend is a boring person)
You can use these adjectives to describe people or situations but be careful that you are using the correct adjective. For example, there is a big difference in meaning between:
I am confused. – (I don’t understand something)
I am confusing. – (I will cause you to be confused)
The sentences below are to show you the difference between the two types of adjectives. They are NOT common to do or say because they sound repetitive.
I was shocked by how shocking the accident was last night.
They were frightened by the frightening roller-coaster ride!
I am annoyed by how annoying that person in front of us is.
Sally was confused by the confusing street signs in the city.