A sentence can be formed with normal parts of speech, consisting of a subject, a verb sometimes using an object too. But sometime people say, for example “why not have him over to come to the party on the next weekend? Instead of “why not invite him to come to the party on the next weekend? By the way I'm starying to understand that using phrasal verb can indicate someone (he or she) is able to speak english more fluently than someone who doesn't. Or maybe that’s just a common form of conversation for a native speaker. Is that true?

Yes, phrasal verbs are very in native speech. They often seem more natural or colloquial to us than alternative ways of saying something which do not use them.