The keyword phrase is a noun phrase, with the primary part of speech being the head noun, "cast".
In a grammatical analysis, "cast" serves as the core subject. The subsequent words, "of a patriots day film," form a prepositional phrase. This phrase functions adjectivally, modifying the head noun "cast" by specifying which group of actors is being discussed. Within this prepositional phrase, "film" is the object of the preposition "of," and it is modified by the noun adjunct "patriots day."
Therefore, the main point of an article using this keyword must be the "cast"the collective group of actors. The phrase "of a patriots day film" simply provides the specific context, narrowing the topic to the actors associated with that particular motion picture. The grammatical structure dictates that the focus is on the people, not the film itself or the historical event.
