Some students find the concept of nominals to be confusing. Remember that nominals are simply another constituent of grammar. Like other constituents such as phrases and clauses, they function as units. Like phrases, nominals also have heads. Remember that head words are important because their features play a role in how the entire phrase functions within the sentence. That's why we name the phrase after the category of its head word. One way to think of this is that the properties of the word carry over to the phrase. Looking at how this works in a tree diagram, we can think of the properties of the head word as percolating up from the individual word to the phrase. The following diagram represents this "percolation" by showing the edges between the head words and their parent nodes as arrows.[1]

Let us pause a moment to take stock of our NP structure. We've only looked at a few relatively simple NPs, but already we have a number of different cases:

1.One-noun NPs, e.g., John, students,
2.Determinative + N, e.g., that book, Alison’s divorce,
3.Determinative + modifier + N, e.g., the unpleasant boy,
4.Determinative + N + modifier, e.g., the dog on the sofa.

Is there any general pattern here? We can easily formulate a general principle for cases 3 and 4 if we say that dependents other than determinatives combine to form nominals, whether those dependents appear before or after the head noun, and determinatives combine with nominals to form NPs.

Noun phrases don't just contain nouns and determinatives, of course. They also contain elements such as adjectives.

(13) these diligent workers

In (13) the adjective diligent is a modifier of the head noun workers. Modifier is a general term for optional elements in a phrase that add descriptive information about the head word. We have already seen some modifiers in the verb phrase: the adjuncts. The noun phrase also resembles the verb phrase in that it can contain contain complements. Distinguishing modifiers from complements in noun phrases, however, is much trickier than distinguishing them in verb phrases, and we will not do so in this course. Instead, we will content ourselves with simply lumping noun-phrase modifiers and complements into the broader category of dependent.

Another fairly common type of NP is one containing a genitive:

(7) Garth's reply

This NP looks almost the same as the NPs above, but Garth is a proper noun, not a determiner. And yet Garth seems to occupy the same "slot" in the noun phrase. Notice that we can use either a determiner or the proper noun, but not both:

(7a) the reply
(7b) *the Garth's reply
(7c) *Garth's the reply

At this point, you may be ready to assume that Garth’s actually is a determiner, but that conclusion leads to some unfortunate consequences. First, we would have to say that any noun could change its part of speech simply by adding the genitive inflection. In other words, the category of determiner, which we have already described as containing a small number of words that have a principally grammatical function becomes an open-ended set. Further, this slot isn't just occupied by genitive nouns. It can be occupied by entire phrases:

As the preceding discussion shows, some nouns can appear alone in a noun phrase, without a determiner or any other word. These nouns include many proper nouns, mass nouns, plural count nouns, and pronouns. (Remember, we are treating pronouns as a subtype of nouns.) Diagrams of such phrases are about as simple as they come:

[1]

Only a little more complex is the case of a noun appearing with a determiner. Determiners are extremely common in noun phrases. You will encounter a great many noun phrases that contain them. If you are still unclear about the category of determiner, you may want to review the relevant section of chapter 3 at this point

Pronouns are words like he, she, or you that let us cross-reference another entity somewhere else in the discourse or in the real world. Traditional grammars state that pronouns replace nouns, but it would be more accurate to say that they replace noun phrases.

(12a) [The airplane parked on the tarmac] appeared damaged.
(12b) It appeared damaged.

In (12b), the pronoun it does not replace just the word airplane of (12a); it replaces the entire string of words, the airplane parked on the tarmac. Replacing only airplane with a pronoun yields an ungrammatical sentence: