The main point of the keyword phrase is the first instance of "September 11," which functions as a proper noun. It is not merely a date but the specific name of a historical event: the terrorist attacks that occurred in the United States in 2001. Like other named events such as "the Holocaust" or "the Cold War," it is treated as a singular, identifiable entity.
Grammatically, the full phrase "september 11 on september 11th" separates the subject from a temporal modifier. The initial "September 11" is the subject (the proper noun, representing the event), while the prepositional phrase "on september 11th" acts as an adverbial phrase, specifying the date on which the event took place. This distinction is critical; the article's focus is the event itself, not the calendar date in general. The capitalization of "September 11" in formal writing reinforces its status as a proper noun.
Identifying "September 11" as a proper noun is crucial for the article's scope and focus. It establishes that the subject is the multifaceted eventincluding its political, social, and historical context and consequencesrather than a simple chronological description of a day. This linguistic classification directs the writing to treat the topic as a significant, named phenomenon with a distinct identity and legacy, guiding both the author's analysis and the reader's understanding.
