The keyword phrase "patriots day tamerlan" functions grammatically as a proper noun phrase. It operates as a single unit to name a specific subject: the individual Tamerlan Tsarnaev in the direct context of the events that occurred on Patriots' Day, most notably the 2013 Boston Marathon bombing, or his portrayal in the 2016 film Patriots Day.
This classification is derived from the combination of its two components. "Patriots Day" is a proper noun, referring to a specific holiday and, by extension, the film title. "Tamerlan" is also a proper noun, the first name of Tamerlan Tsarnaev. When juxtaposed, they create a compound subject that narrows the focus from the general individual to his specific role and actions associated with that event. The phrase does not describe an action (verb) or modify another noun (adjective); it names the precise entity to be discussed.
Understanding this grammatical function is crucial for structuring an article because it establishes the central subject matter. As a noun phrase, it dictates that the article's purpose is to describe, analyze, or explain this specific topic. The content would revolve around the character, actions, motivations, or depiction of Tamerlan Tsarnaev as inextricably linked to the Patriots' Day event, rather than a broader biography or a general discussion of the holiday itself.
