The keyword "patriots day film length" is a noun phrase. The primary part of speech that represents the main point of this phrase is the head noun, which is "length". The entire phrase functions as a single grammatical unit to name a specific attribute or piece of information.
In this construction, "length" is the core subject. The preceding words, "Patriots Day" (a proper noun) and "film" (a noun), act as noun adjuncts or adjectival modifiers. They serve to specify and narrow down the head noun. The term "film" modifies "length" to clarify the type of length being discussed (duration, not physical dimension). Subsequently, "Patriots Day" modifies "film length" to specify the exact subject: the duration of the particular movie titled Patriots Day.
Recognizing "length" as the key noun is critical because it establishes the article's primary intent: to provide a specific, quantifiable piece of data. The article's main point is to answer the implicit question, "What is the duration of the film Patriots Day?" The content should therefore be focused on stating this value (e.g., 133 minutes) and providing any relevant context, as the keyword is a direct query for a factual attribute.
