The keyword term "Patriots Day holiday in Massachusetts" functions as a noun phrase. The central and most crucial part of speech within this phrase is the noun "holiday," which serves as the head of the phrase.
A detailed grammatical analysis reveals the function of each component. "Holiday" is the core noun, identifying the subject's category. "Patriots Day," a proper noun, acts as a noun adjunct (or adjectival modifier), specifying which particular holiday is being discussed. The prepositional phrase "in Massachusetts" functions as an adjectival phrase, further modifying the noun "holiday" by specifying its geographic location or context. The entire construction names a single, specific entity.
Understanding that the keyword is a noun phrase is critical because it establishes the article's main point as a specific thing or concept. As a noun phrase, it can act as the subject of a sentence (e.g., "[Patriots Day holiday in Massachusetts] is a unique observance.") or the object of a verb or preposition. This grammatical structure solidifies the topic as a tangible event to be described, explained, or analyzed, rather than an action or a description.
