The keyword phrase functions as a noun phrase. In this construction, "birthdays" is the head noun, which identifies the core subject. The term "september 11th" serves as a nominal adjective (a noun used as an adjective) that modifies the head noun. This grammatical structure establishes the main point of the article as a specific group or category of events.
Grammatically, the proper noun "september 11th" is used attributively to specify the temporal attribute of the noun "birthdays." This is a common syntactical pattern in English where one noun qualifies another, such as in "summer vacation" or "business meeting." The analytical step is to deconstruct the phrase to identify the primary subject ("birthdays") and its defining characteristic ("september 11th"). This clarifies that the article's focus is on the events themselves, as framed by the significant context of the date.
This classification is crucial for practical application in writing the article. Since the keyword is a noun phrase, the article's subject is a concept or a thingthe experience of individuals who have birthdays on this date. The content should therefore explore the attributes of this subject, such as the personal stories, the unique emotional weight, or the cultural significance associated with these specific celebrations. The grammatical structure dictates that the article must address the "what" (the birthdays) as its central theme, rather than treating the date merely as a setting.
