# Pattern of age *be 16 years old*

I have always wondered how to classify this kind of clause:

He is fifty-four years old

How should it be classified?

Either as:

• He (Subject)
• years (countable noun)

Or as:

• ...
• ...
• Fifty-four (Cardinal number, determiner)
• ...
• ...

You are mixing syntactic functions (how words and phrases relate to each other within the context of a sentence) with parts of speech or word categories (how words are classified on an individual basis).

"He is fifty-four years old" is a sentence formed by:

• Subject: "He"
• Predicate: "is fifty-four years old"

Within the predicate, we have:

• Linking or copulative verb: "is"
• Subject complement: "fifty-four years old"

And here comes the most challenging part: deciding how the subject complement is structured and works.

To me, a feasible parsing would be saying that "old" is the head of the subject complement and that the noun phrase "fifty-four years" premodifies "old". Actually, that sentence can be the answer to the question:

• How old is he?

in which "how" (just as "fifty-four years" in the answer) intensifies or modifies "old".

• Thanks for your answer. In fact, every sentence can be differently structured, but this is not the case in my question; there are only two ways to interpret that predicative nominal (is fifty....), if you look back at the patterns provided, you will see that there is no other way that this sentence can be phrased, so there are only two explanations for such a sentence, and they were also provided in my question. I will summarize it for you: The real question is: How do people see "fifty-four"? As an Adjective modifying "years" or a Determiner? Jul 16, 2017 at 0:46
• @Prodigy I'm sorry I can't see your point. Adjectives and determiners are close to each other -- they both modify nouns. Classifying "fifty-four" as an adjective or as a determiner does not change how the phrase in question can be analyzed. To me, the point is whether "years" or "old" is the head of the subject complement. I'd go for "old", for the reasons I provided. Jul 16, 2017 at 1:50
• There is, indeed, a difference between Determiners and Adjectives: Determiners and Adjectives do indeed modify nouns and form noun phrases; however, Determiners are limited to a certain number, for example: You can't have quantifier and a numeral, which are both determiners, in a noun phrase: The two many people or The many two people, from that, we can notice that they are limited to a certain number and determiners; whereas Adjectives belong to "Modifiers", along with Prepositional Phrases, To-infinitive phrases and Relative Clauses and Compound Nouns; they are ilimited: Jul 17, 2017 at 13:55
• I can have: The beautiful, long, charmful, adorable and amazing hair with a beautiful tiara and a nice color around belongs to the girl. As you can see, I can have multiple modifiers, while Determiners are limited to a certain number. Jul 17, 2017 at 13:57