Hi Raychatu Sanfo,
Let's take a look at this sentence: Tim is a very interesting speaker and I was very interested in what he has to say.
As you can see, both "interesting" and "interested" are adjectives, with "interesting" describing Tim's ability or quality while "interested" describes my attitude towards him.
They are related because someone who is "interesting" (a quality) CAUSES someone else to be "interested" (a state of mind). Yet, they are different because they have different meanings.
In fact, these are participial adjectives (verbs that end suffixes such as -ed and -ing) but are used as adjectives. Some participial adjectives have this relationship where the -ing form describes a person or situation while the -ed form describes a state of mind.
This is boring show. (Situation)
I am so bored. (State of mind)
There will be an exciting plan. (Situation)
The kids are so excited. (state of mind)
I hope this helps.