Why are you so cruel to me?
That was a very cruel thing to do.
you are as cruel as a tiger
In the 1960's people were very cruel to blacks,
The citizens were oppressed by their cruel dictator.
Example sentence - She would have readily have forgiven him but he continued to be cruel so she left him.
Oxymoron is the word you are looking for.Example:'He looked at her with cruel kindness'.The expression 'cruel kindness' is an oxymoronbringing out a self-contradictory effect in the sentence.
The jocks at school are cruel to the nerds.My brother is cruel to me because I beat him at video games.
Infidelity is rampant among the selfish, cruel leaders.
Do not be cruel to animals.Why are you so cruel to me?Her actions were very cruel.
To be diabolical is to be extremely cruel. An example sentence would be: Some people say Hitler's acts were diabolical.
Cruel means deliberately mean or hurtful. Here are some sentences.You were very cruel to that poor man.She was a cruel stepmother to Cinderella.The cruel treatment of prisoners is morally wrong.
"Can you use cruel in a sentence?" is a sentence, so yes, unless you mean something else?
The form of "cruel" that would be considered an abstract noun would be "cruelty".