He is really an ungrateful person.

He completely forgot my help, acting like an ingrate.

He is working hard to make his abilities known to the world.

He is still young and ignorant of the ways of the world.

Because he was raised in the countryside, he is completely ignorant of city life.

He was said to be as beautiful as a seraph.

That person is my friend.

He is truly a wonderful person.

There are 20 students in our class.

He is a true gentleman.