What are the differences between these two sentence in meaning?
He tends to exaggerate. "and" He is exaggerated.
Please also explain the differences between
He tends to be selfish. "and" He is selfish.
"He tends to be selfish" means that he is sometimes selfish, or even frequently selfish.
"He is exaggerated" is incorrect and meaningless.
See probus's response in post #2 and this definition.