12 March, 2010

Lecture 2- Phrasal Categories

Phrasal Categories: (syntactic labels): NP, VP, PP, Adj, Adv, Det, Linear order and internal hierarchical structure. Just as morphemes have morpheme categories, and words have word categories, phrases have phrasal categories.
Phrasal categories, just like word categories, are ultimately much more useful than just individual phrases, for the study of sentence structure. A phrasal category is directly determined by the category of the word which the phrase is about. Such a word is called the head of the phrase.
How to determine a phrasal category:
The concept of a “head”
• The head of a phrase is the main word of that phrase. It is essentially what the entire phrase is about.
• The category of a phrase is directly determined from the category of its head.
To see how this works, consider the following example sentence, with the phrases marked out in brackets:

(1) [The tiny woman] [went [to [the store ] ] ]

Sentence (S) = The tiny woman went to the store

Phrase 1 = the tiny woman

Phrase 2 = went to the store

Phrase 3 = to the store

Phrase 4 = the store

What is the head of Phrase 1?
In other words, what is Phrase 1 mainly about? What does it refer to in the real world?
It is essentially talking about a woman. The other words the and tiny give us more information about the woman but this is extra information. The main word in the phrase is woman.
So, the head of Phrase 1 is woman.
Determining the phrase category
What is the category of woman? It is a noun.
• The category of the phrase is determined by the word category of its head.
The word category of the head is: Noun.
• Therefore, the phrasal category of Phrase 1 is: Noun Phrase (NP, for short).
Similarly, in Phrase 2, the head is: went because this is the main information.
That the woman went to the store (and not somewhere else) is extra information. So, the head of Phrase 2 is: went. The word- category of went is verb. So, Phrase 2 is a Verb Phrase (VP).
In Phrase 3, the head is: to. Even if it doesn’t seem so obvious, the phrase is actually talking about the woman going to a place, so the head of this phrase is to. The category of to is preposition. So,Phrase 3 is a Prepositional Phrase (PP).

Lecture 1- Preliminaries

Syntax is the branch of linguistics which deals with the study of sentence structure.

Syntactic categories
A syntactic category is either a phrasal category, such as noun phrase or verb phrase, which can be decomposed into smaller syntactic categories, or a lexical category, such as noun or verb, which cannot be further decomposed.
The three criteria used in defining syntactic categories are:
1. The type of meaning it expresses.
2. The type of affixes it takes.
3. The structure in which it occurs.
In terms of phrase structure rules, phrasal categories can occur to the left side of the arrow while lexical categories cannot.
The lexical categories are traditionally called the parts of speech. They include nouns, verbs, adjectives, and so on.
words are the units that make up a sentence.
• This is indeed true and a study of words and, especially, of the categories of words (like NOUN, VERB, ADJECTIVE) is crucial to understanding sentence structure.
Word categories
Word categories are crucial to the study of sentence structure. In fact, they are more important than words.
• When we say word category, we mean categories like NOUN, VERB, ADJECTIVE but also less well-known categories, which we’ll learn about, like determiner and auxiliary.
• In last week’s class, we also referred to a word category as part-of-speech. These two things mean exactly the same thing.
Why are word categories more important than words
Words vs. word categories
Before we go on to study word categories, it is important to ask this question:
Why are word categories more important than words for sentence structure?
Here’s why word-categories are more important than words:
Reason 1: Different words, same word categories.
What makes one sentence different from another sentence?
(i) Each sentence has different words
(ii) Each sentence has a different order of words.
• So a sentence analysis which only looks at the words (and the order in which these particular words occur) in a sentence - will only be relevant to that particular sentence, not to any other.
• Such an analysis will not be very interesting because it cannot be used to generalize about other sentences or to understand how other sentences are structured in a language.
• However, word categories (like NOUN, VERB, ADJECTIVE, etc) are shared by all sentences.
• So an analysis that is made in terms of word categories and their relative order in a sentence is a better analysis than one that is based on individual words.
(2) This child cries.
(3) The bird sings.
• Both sentences have completely different words.
• And yet, in terms of word-categories, the two sentences have the same structure, which can be represented as :ARTICLE - NOUN - VERB
• If we just studied individual words, we would have no clue that these sentences actually have the same structure. Each sentence would then get a differentstructure” because they have different words - and we would miss the similarity in the structure of the two sentences entirely.
Reason 2: A sentence can contain an infinite number of words.
Consider the following sentence:
(4) I saw the child on the swing under the apple tree in the garden by the white fence that was along the road with the cars . . .
• It’s simply not practical, or possible, to study the individual words in the above sentence because there could be an infinite number of words in it!
• It’s much easier to study word categories because we can then generalize across several types of words.
• For e.g., we could say that the above sentence just has a standard NOUN-VERB-NOUN structure that is then followed by a repeating pattern of PREPOSITIONS followed by ARTICLES and NOUNS.

The myth about word categories

Word categories

Now that we have seen that word categories are so important, let’s look at them!
You might have already learned to identify categories like NOUN, VERB, ADJECTIVE, PREPOSITION, ADVERB and so on, as follows:
• A NOUN is a person, place, or thing.
• An ADJECTIVE describes qualities typical of a NOUN.
• A VERB denotes an action, event, state, or emotion.
• An ADVERB describes qualities of a VERB, ADJECTIVE, or other ADVERB.
• A PREPOSITION describes a spatial or temporal relation, direction toward or away from something, and alternatives (except, despite).
These descriptions of the meanings of word categories are definitely helpful to some degree.
Because of descriptions like these, you can easily identify the categories or parts of speech of sentences like this:
(5) John drives very fast on highways. (NOUN = John, highways; VERB = drives; ADVERB = very; ADJECTIVE = fast; PREPOSITION = on)
But what about sentences like this?
(6) I wondered whether he felt too angry.
(7) His destruction of the school was terrible
(8) In order for such a plan to work, we need lots of money!
(9) It is raining.
• Of course, we can identify some words like assumptions, and light bulb as NOUNS and we can also identify some other words like felt, work and raining.
• But what about words like order in example (8)? We know that it must be a NOUN, but we couldn’t really know that from the definition for NOUN above: it’s not a person or a place, but it doesn’t really seem to be a thing either‘.
• And what about destruction in (7)?DESTRUCTION' is a type of action and, according to our definition, it should be a VERB. But we very well know that it’s not a VERB; that it is, in fact, a NOUN!
• Finally, words like whether in (6), a in (8), and it in (9) don’t seem to have any clear meaning at all.
Nonsense words
Examples like the above suggest that a mere semantic description of the word categories is not enough.
But conclusive evidence that they are not all that helpful at all comes from examples like the famous Jabberwocky poem by Lewis Carroll.
Jabberwocky, by Lewis Carrol
‘Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe.
Beware the Jabberwock, my son!
The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
The frumious bandersnatch!
The above poem contains some actual English words, but it also contains several words above that are not English but nonsense-words.
• And still, we can identify what word categories these nonsense words belong to!
The fact that you can identify the word categories of nonsense words or words that have no semantic meaning whatsoever shows that there is more to a word category than just semantic meaning.So we need a better way to describe word categories - one that doesn’t just use semantic descriptions of NOUNS, VERBS, . . . .
A better definition for word categories
Two things probably helped you to figure out the category of the nonsense words:
• The affixes on the word. e.g. the morpheme -ous in frumious.
• The position of the word in the sentence gives a further clue. e.g. that Jabberwocky occurs immediately after the.
• Evidence like word-affixes constitute morphological properties of word categories; the affixes themselves are called morphemes.
• Evidence like word position constitute syntactic properties of word categories.
• Together, the morphological and syntactic properties of a word provide far more effective evidence for determining word categories than semantic properties.
We can now provide better definitions for word categories like NOUN, VERB, ADJECTIVE, ADVERB and PREPOSITION (for English) in terms of their syntactic and morphological properties.