The grammatical function of the keyword is a noun phrase. The core element is the proper noun "Patriots Day," which is subsequently identified and described by the appositive phrase "a holiday in NH."
An appositive is a noun or noun phrase that is placed next to another noun to rename or provide more information about it. In this construction, "a holiday in NH" serves as the appositive to "Patriots Day." This appositive itself contains a head noun ("holiday") which is modified by a prepositional phrase ("in NH") that specifies a geographical location. The entire construction acts as a single, cohesive nominal unit.
Understanding this structure is crucial because it dictates how the keyword can be used within a sentence. As a noun phrase, it can function as a subject (e.g., "[The keyword] commemorates the first battles of the American Revolution."), a direct object, or an object of a preposition. This grammatical classification is the foundation for constructing clear and accurate sentences about the topic.
