Syntactic Rules

Syntax is the study of the structure and ordering of components within a sentence. It comes from the Greek word meaning “putting together” or “arrangement.” Syntactic analysis should be “all and only”. This means it must account for all grammatically correct phrases and only those grammatically correct phrases. A goal is to have a finite and small set of rules called generative grammar that can produce an infinite number of well-formed structures. This should enable us to differentiate between superficially similar phrases that are different and superficially different phrases that are closely related.

Deep and Surface Structure

Surface structure is the structure of individual sentences in contrast to deep structure which is the underlying structure of sentences as represented by phrase structure rules. Phrase structure rules are rules stating that the structure of a phrase of a specific type consists of one or more constituents in a particular order.

For an example look at the following sentence, it is written in surface structure level.

My wife’s parents treat my children differently because they are handicapped.

Now ask yourself who is handicapped? My wife’s parents or my children? Well we don’t know! But if we rewrite it in deep structure it becomes clear:

My wife’s parents are handicapped and treat my children differently.

Structural ambiguity is not the same as ambiguity. Lexical ambiguity is when a word has more than one meaning. Structural ambiguity occurs when a phrase or sentence has two or more different underlying structures and interpretations.

Syntactic Analysis

Syntactic analysis allows us to investigate the underlying structures. It uses conventional abbreviations listed below.

The above image isn’t very dynamic so we can instead use an arrow (→) to say “consists of” or “rewrites as”. To visualise the rule that a noun phrase contains an article and a noun we can write is as: NP → Art N. But we know that there can also be an adjective as in the image above so we can write the adjective as optional so it becomes: NP → Art (Adj) N. We also know that a noun phrase can be a pronoun or a proper noun so we can rewrite the “definition” of a noun phrase like this: NP → {Art (Adj) N, Pro, PN}, where one can only select one element enclosed within the curly brackets separated by the comma.

Phrase structure rules state that the structure of a phrase of a specific type will consist of one or more constituents in a particular order.

Lexical Rules

While phrase structure rules generate structures they are not recognizable English. Lexical rules specify which words can be used when we rewrite constituents. They are shown similarly to phrase structural rules. If we live in a world with only three names the lexical rule for pronouns would look like this: PN → {Bob, Joe, Sandra}, likewise articles look like this: Art → {a, an, the}.

Tree Diagrams

Tree diagrams shows with branches the hierarchical organization of structures. This allows us to convert NP → Art N to:

We can use a similar structure to represent more complex structure such as the following verb phrase:

Study Questions

1. What was the original literal meaning of syntax in Greek? Putting together or arrangement.
2. What is wrong with the following rule of English syntactic structure?

A prepositional phrase rewrites as a preposition followed by a noun.

It will produce grammatically incorrect structures. Should instead have preposition followed by a noun phrase.

3. What is the main difference between a generative grammar and a traditional grammar? Generative grammar produces sentence structure while traditional grammar describes sentence structure.
4. At what level of structure are these two sentences different?

A large dog attacked us. / We were attacked by a large dog.

Their surface structure is different.

5. Which of the following expressions are structurally ambiguous?

a. These are designed for small boys and girls.

b. The parents of the bride and groom were waiting outside.

c. How come a bed has four legs, but only one foot?

d. We met an English history teacher.

e. Flying planes can be dangerous.

f. The student complained to everyone that they couldn’t understand.

Everyone except C which shows lexical ambiguity.

6. What part of speech is lovely in the following sentence? Adjective

We saw a lovely rainbow yesterday.

7. How many noun phrases are there in the following sentence? 8

George saw a small dog in the park near the fountain and it followed him when he left the park.

8. Which part of the following sentence is the VP? “supported the proposed rent increase”

None of the people in the building supported the proposed rent increase.

9. Which of the following expressions would be generated by this phrase structure rule: NP → {Art (Adj) N, Pro, PN}?

10. What kind of generative rule is this: N → {girl, dog, boy}? Lexical rule Revise!
11. Do phrase structure rules represent deep or surface structure? Deep structure.
12. Complete the following tree diagrams.