23 Structure within the sentence
From words to phrases
Beyond the order of words, all human languages appear to group words together into constituents. The generalizations about which sentences people find grammatical and which ones they find ungrammatical don’t refer to purely linear properties like “fourth word in a sentence”, but instead to phrases in particular structural positions. In the rest of this section we’ll explore what it means to be a phrase in more detail; in the next section we’ll start talking about structural positions.
A phrase is a set of words that act together as a unit. Let’s look at the example in (1) to see what this means:
| (1) | All kittens are very cute. |
What other groups of words can appear in the same position as the words all kittens in this sentence?
| (2) | a. | Puppies are very cute. |
| b. | The ducklings that I saw earlier are very cute. | |
| c. | These videos of a baby panda sneezing are very cute. |
…and so on. It turns out that lots of different groups of words can go in this position—but not all of them! What all these examples have in common is that we’ve replaced [all kittens] with another group of words that includes at least one plural noun: puppies or ducklings or videos. If we swap in a singular noun, the sentences would be ungrammatical, as we see in (3).
| (3) | a. | *The puppy are very cute. |
| b. | *The duckling that I saw earlier are very cute. | |
| c. | *This video of a baby panda sneezing are very cute. |
…but if we change the plural verb are to the singular is they become good again (this is subject agreement inflection):
| (4) | a. | The puppy is very cute. |
| b. | The duckling that I saw earlier is very cute. | |
| c. | This video of a baby panda sneezing is very cute. |
It turns out that the groups of words that we can easily substitute here are all ones that have a noun in them. But it’s not enough to just have some noun in the group of words at the front of the sentence, as the examples in (5) show. (5a) is ungrammatical even though the string of words at the beginning includes the pronoun I—and this sentence is ungrammatical whether we try the form is or are or even am. In (5b) the sentence is ungrammatical even though we have the compound noun baby panda, again no matter what form of the verb we try.
| (5) | a. | *That I saw earlier {is / are / am} very cute. |
| b. | *Of a baby panda {is / are} very cute. |
What distinguishes the grammatical sentences in (1), (2), and (4) from the ungrammatical sentences in (5) is that in (1), (2), and (4) the group of words at the beginning of these sentence are noun phrases (remember that the sentences in (3) were ungrammatical just because they had the wrong agreement inflection). Noun phrases are groups of words that not only contain a noun, but where the noun is the “most important” element in some sense.
By “most important” we mean that it’s the noun that determines an important part of the meaning of the subject, but also that it’s this