To use ashamed in a sentance, you could say, I hope that you are ashamed of yourself, or, I feel very ashamed at what I did.
Patty was extremely ashamed.
I was ashamed of the fact I cheated in my exam
He was ashamed of himself because he did not study for the exam.
The child was ashamed to tell her mother why she had to serve a detention at school.
He was ashamed of what he had done.
The teacher's dismay at Billy's answer made him feel ashamed.
Here is one example of such a sentence: 'You are right to feel ashamed of your behaviour towards your parents; it has been appalling.'
"With the recent events involving SOPA and PIPA, I have begun to grow ashamed of the way America is turning out."
She felt ashamed when she realized she had forgotten her friend's birthday.
I discredit my friend from the spelling bee contest and I am ashamed
Feeling ashamed and contrite, I apologised for treating him so rudely.
the ashamed children relinquished their stash of candy.