The keyword term is an adverbial phrase of time. Its primary grammatical function is to modify a verb, an adjective, or another adverb by specifying precisely when an action or event occurred in the past relative to the present.
This phrase is a composite structure. It contains the noun phrase "911 days," which quantifies a specific duration of time. This noun phrase is then governed by the adverb "ago," which functions here as a postposition. A postposition is a word that follows its complement, in this case, "911 days." The entire unit works cohesively to answer the question "when?" and provides temporal context to the main clause of a sentence.
Understanding this grammatical function is crucial because it defines the article's core subject: an event or state of being that is anchored to a specific point in the past. For the article to be effective, its content must directly address this temporal anchor. Correctly identifying the phrase as an adverbial allows for proper sentence construction and ensures the article's focus remains aligned with the precise historical or time-sensitive nature of the keyword.
