The keyword term "September 11th worksheet" functions grammatically as a compound noun or a noun phrase. The primary or head part of speech, which represents the core subject, is the noun "worksheet".
In this construction, "worksheet" is the head noun, identifying the object. The preceding term, "September 11th," is a proper noun used as a noun adjunct or adjectival modifier. It specifies the theme, content, or subject matter of the worksheet. Its function is to describe the noun, answering the question, "What kind of worksheet is it?" The entire phrase operates as a single unit to name a specific type of educational document.
For the article's main point, the crucial element is the head noun, "worksheet." This establishes that the subject is a tangible or digital educational resource. The modifier "September 11th" provides the specific context. Therefore, the article is fundamentally about a type of worksheet, making noun the most important part of speech to consider for the core topic.