The keyword phrase functions grammatically as a compound proper noun. This classification identifies the term not as an action or a description, but as the specific name of a unique, annually recurring cultural event.
The phrase is composed of two distinct proper nouns: "Patriots' Day," a regional public holiday, and "Red Sox," the name of a professional baseball team. When combined, they form a single nominal unit that refers to the traditional morning baseball game hosted in Boston on that holiday. In grammatical analysis, while the components could be seen as modifying an implied noun (e.g., "game"), the phrase as a whole has become a standalone signifier for the event itself, functioning as the subject or object in a sentence.
Recognizing the term as a compound proper noun is a crucial step for the article's focus. It establishes the subject as a specific entity with its own history, traditions, and cultural significance. This grammatical determination dictates that the article's main point must be an exploration of this event, rather than a general discussion of the team or the holiday in isolation, thereby framing the topic as a distinct institution to be described and analyzed.
