The keyword phrase "11 sep new york" functions as a proper noun. It operates as a single semantic unit to name a specific, significant historical event: the terrorist attacks that occurred on September 11, 2001, in New York City.
Grammatically, the phrase is a compound noun phrase. It consists of a date ("11 sep") and a location ("new york"), which together form a unique identifier for the event. In a sentence, this phrase would occupy a position typically held by a noun, such as the subject ("11 sep new york changed the world") or the object of a verb or preposition ("The article is about 11 sep new york"). It does not function as a verb, as it expresses no action, nor as an adjective, as it is not modifying another noun but is the name of the subject itself.
Recognizing "11 sep new york" as a proper noun is the main point because it dictates the grammatical structure of sentences within the article. It ensures the phrase is treated as the central subject or topica specific, named entityrather than a collection of descriptive words. This focus is essential for maintaining clarity and establishing the event as the core subject matter of the text.
