The subject can be any thing, a person, name, place, an animal, etc.
Example: Dog, Park, John.
Main Verb.
Nota:
The main verb is invariable in past participle form: ed (or irregular).
Auxilary have.
Nota:
The auxilary "have" has to be in past simple form, "Had"
Complement
Nota:
The complemente is using to give extra information to make more complete the senence, can be any thing.
Example: With my friend, tomorrow nigth, in the classroom, etc.