The keyword phrase "patriots day film dzhokhar tsarnaev" functions as a compound noun or a complex noun phrase. The main part of speech, which serves as the core subject or head of the phrase, is the noun "film".
In this grammatical construction, "film" is the central element being described. The other words act as modifiers, specifically as noun adjuncts, to specify which film is the subject. "Patriots Day" is a proper noun that identifies the title of the film, functioning adjectivally. "Dzhokhar Tsarnaev" is another proper noun that further modifies "film" by specifying a key character or subject matter depicted within that cinematic work. The entire phrase narrows the topic from the general concept of a film to a specific movie titled "Patriots Day" that involves the character Dzhokhar Tsarnaev.
For the purpose of an article, this determination is crucial because it establishes that the primary topic is the cinematic product ("film"). The content should therefore focus on the movie's portrayal, production, narrative, or analysis concerning its subject matter, rather than treating the historical event or the individual as the primary subject independent of their depiction in the film.
