In the dark it was hard to notice the person standing in the shadow.
Some consider an animal pet as a person, which it is not.
You use he or she when you already have referred to a person in a sentence before, or earlier in the same sentence.
"I have a problem." "I" is used when the first person is the subject of the sentence.
You are not a seraphic person.
you are an impeccable person
You are a fascists person
A person who is caucasian is normally a white person.
This is how I would use ribaldry in a sentence: Mark is a very ribaldry person. Because the definition of ribaldry is a vulgar, lewdly, funny person.
A person who is opposed to the use of war
Some people believe in aliens. Alien is a noun so use it in a sentence as a person
Ashley is a vulgar person
His boss was a morose person.
That person is from a foreign country.