Syntax 1 (12-Feb-2004)
Background
In order to perform syntactic analysis, it is important to be aware of the
criteria for the word classes:
- nouns
- verbs
- adjectives - adjectives have degrees (e.g. sweet, sweeter, sweetest) and
can often be turned into adverbs (sweetly)
- prepositions
- determiners and auxiliaries are useful as well
There are many exceptions, but in general there are standard criteria to
decide what counts as an adjective, verb etc..
What happens when syntax goes wrong?
Pinker (p292) reports on the case of "Chelsea" who was born deaf and
misdiagnosed as mentally retarded, until at age 31 an operation restored her
hearing. Although she has since developed a vocabulary of two thousand words,
her ability to form syntactically correct sentences is lacking, e.g.
- The small a the hat
- Banana the eat
- The woman is bus the going
This contrasts with the result of studies of three children below the age of 5
in the Harvard study, where only ten out of many thousands of utterances
showed syntactic position errors. Syntax relates to the ability to order
grammatical elements correctly into a sentence, and this appears to be a
separate ability to, e.g. morphology.
Categories of syntactic phrases
Syntax allows a phrasal constituent to substitute for a single word
of a specific class. For example, a noun phrase is built on a single
noun, and any sentence which contains a slot for a noun can receive any noun
phrase in that slot while retaining syntactic sense.
The group of words that forms a phrasal constituent must remain together in
an appropriate "slot" in the sentence: it may move around as a whole, but
cannot be broken up. For example, the noun "birds" may be replaced by the
noun phrase "a large bird with an orange beak", but that noun phrase must
remain a single unit:
- birds ate some food
- some food was eaten by birds
- the large bird with an orange beak ate some food
- some food was eaten by the large bird with an orange beak
but you can't break it up and retain the sense:
- *some the large bird food was eaten by with an orange beak
The slot occupied by a given noun phrase can be replaced by any other valid
noun phrase and retain syntactic sense (although the semantic meaning may not
be valid):
- a cat ate some food
- some food was eaten by a cat
- *a some food was eaten by cat
The verb "waited" can be replaced by a verb phrase:
- The young man waited
- The young man waited for his friend
- The young man has waited for his friend
- *The has waited young man for his friend
The head word of a noun phrase is a noun, the head word of a
verb phrase is a verb, etc.. The rest of the phrase complements the
head word, completing its meaning. If a phrase in a sentence can be replaced
by a noun, we know that the phrase is a noun phrase.
How else can we determine what counts as a phrasal constituent?
Apart from testing whether a word or phrase can substitute in a sentence for
another word or phrase, there are other criteria we can use in trying to
decide whether a given series of words is a phrasal constituent:
- is it a conceptual unit, or a unit of sense?
In some cases, e.g. a noun phrase, it's fairly easy to say that "a red hat"
is a conceptual unit, whereas the first three words of the sentence "you know
how to do this" don't seem to be. Anything which is a conceptual unit will be
a phrasal constituent (although the reverse isn't necessarily true).
In a sentence such as "the girl sailed up the river", up the river
does form a conceptual unit, and this is a prepositional phrase. But
not all prepositional phrases are easy to conceptualise, e.g. "the girl
laughed at the monkey".
The unit of sense criterion seems to work best for noun phrases,
adjective phrases and single verbs.
- can it be replaced by a pro form?
For example, noun phrases can be replaced by pronouns: "she laughed at
the monkey" can be changed to "she laughed at him". Verb
phrases can also be replaced, e.g. "she laughed at the monkey and the boy
did so" - in this case, "did so" means "laughed at the monkey", picking
out the verb and its complement.
If a series of words represents a conceptual unit, then it is regarded as a
phrasal constituent. E.g. "the red hat". However, not all phrasal
constituents are conceptual units. For example, "at the monkey" is a
prepositional phrase: that is, a phrase with a preposition as its head,
and complemented by a noun phrase.
Analyzing the syntax of a sentence
A useful way to break down a sentence syntax involves building a tree of
phrases, starting with the grammatical classes of individual words, and then
finding head words and their complements (if any). For example, in the tree:
S
/ \
/ \
/ \
/ \
/ \
/ \
NP VP
/\ /\
/ \ / \
Det N V PP
. . . /\
. . . / \
. . . P NP
. . . . /\
. . . . / \
. . . . det N
. . . . . .
the bird flew up the chimney
- The sentence (S) consists of a NP and VP : S --> NP VP
- The VP consists of a V and PP : VP --> V PP
- The PP consists of a P and NP : PP --> P NP
- The rightmost NP consists of a det and N : NP --> det N
Syntactic rules are expressed using this terminology, with parentheses
being used for optional components. E.g.
These trees are phrase structure trees or constituent structure
trees. Conventionally, the members of a tree are referred to using
feminine relational terms (mother, sister, etc.).
Note that the phrase structure rules for English not universal: other
languages have different rules.
Useful book readings for this lecture:
- Crystal: "Encyclopedia of Language", pp 94-97
- Fromkin+al "An Introduction to Language" pp 117-137
- Pinker: "The Language Instinct" pp 292-293
Sounds, Grammar and Meaning page