In the keyword phrase "sep 11 bombing," the main point is the word "bombing," which functions grammatically as a noun. It serves as the head of the noun phrase, identifying the core subject or event being discussed.
The term "sep 11" acts as an adjectival modifier, specifically a noun adjunct. It is a proper noun (representing a date) that modifies the noun "bombing" by specifying which particular event is being referenced. While "bombing" can also function as a verb (a gerund or present participle), in this construction it names the event itself, making its role nominal.
Identifying "bombing" as the central noun is essential because it establishes the article's focus on an event or a series of attacks. The modifier "sep 11" then provides the specific temporal and historical context, narrowing the subject from any bombing to the specific attacks that occurred on September 11, 2001. This grammatical distinction clarifies that the subject is the incident, not the date itself.
