Hello,
In “William called out to his friend,” is “called out to” the predicator or “called out”? I say “called out” because “to his friend” can be treated as an adverbial (a prepositional phrase, here) and shifted to the start of the sentence.
TIA,
xtheunknown0
In the strict sense, only ‘called’ would be the predicator, I think. It seems to me that it will take a very idiomatic phrasal verb for the adverbial or prepositional component to be included in the predicator. But I see that the term is also more loosely used, so you should check with your teacher for his definition.