As a keyword term used to define the main point of an article, the phrase "when is patrick's day" functions grammatically as a noun phrase, or more specifically, a nominal clause. In this context, the entire phrase is treated as a single conceptual unit that names a topic of inquirythe date of the holiday. It acts as the subject of the article, much like a standard noun would, allowing content to be structured around providing the answer or information it represents.
Internally, the phrase is structured as an interrogative clause, composed of an interrogative adverb ("when"), a verb ("is"), and a proper noun ("Patrick's Day"). However, when used as a keyword for an article's focus, its function shifts from asking a question to naming the question itself as a topic. This distinction is critical; the article does not simply pose the question but rather addresses the subject matter encapsulated by it. The phrase transitions from a piece of syntax seeking a response to a semantic unit representing user intent.
The practical application of this grammatical classification is foundational to content strategy. By identifying the keyword phrase as a noun-like subject, the article's purpose becomes clear: to provide the referent for that subject. The content is therefore developed to directly define and explain this topic. Consequently, the resolution for the inquiry named by the keyword is that Saint Patrick's Day is observed annually on a fixed date: March 17th.
