The author of the story is implicating that this person is a “hard lump of clay” or a “hard glinty coal” in the sentenc. Notice how in both of these examples they mention the word hard, and an object that is dull. They <em>could</em> be saying that this person was hard to befrend, talk to or whatever the content is and that they seem like a dull person.
For example, let’s call them Henry.
”Henry was a hard person to get to know, he was always very dull.”
The judicial branch of the government decides whether or not laws are constitutional. This is called judicial review and it gives the judicial branch the power to judge or interpret laws to determine if they are constitutional or unconstitutional.
It should be used when you are talking about someone or something that is the most in the group. For example. "The 'tallest' student."