The keyword term "sep 11 planes" functions as a noun phrase. In this construction, "planes" is the head noun, which is the core subject. The term "sep 11," a proper noun representing the specific date and the associated events, acts as a noun adjunct (or attributive noun), modifying "planes." Its role is adjectival, specifying which particular planes are being referred to.
Grammatically, a noun adjunct is a noun that modifies another noun, functioning like an adjective. In this case, "sep 11" is not describing a quality of the planes but is instead classifying them by their direct involvement in the events of September 11, 2001. This structure creates a specific, compound subject that is more precise than "planes" alone. The phrase refers to the four specific commercial aircraftAmerican Airlines Flight 11, United Airlines Flight 175, American Airlines Flight 77, and United Airlines Flight 93that were hijacked and used in the attacks.
By establishing "sep 11 planes" as the main point, an article is framed to focus on these aircraft as the central subjects. The discourse will revolve around the identity, role, and details of these specific entities. This grammatical classification dictates that the article's content will be descriptive and analytical, exploring the aircraft themselves, their flight paths, the passengers and crew, and their function within the historical event, rather than focusing on an action (verb) or a characteristic (adjective).
