Information Technology Reference
In-Depth Information
(
the boy in
(
the park with
(
the red bench
)))
Now, consider the following instead:
the boy in the park with the gray sweater
In this case, the words would be grouped differently, perhaps as follows:
(
(
)
(
))
the boy in
the park
with
the gray sweater
The main point of these groupings is that in the first case, the phrase
with the red
bench
is understood as being connected to
the park
; in the second case,
with the gray
sweater
is understood as being connected to
the boy
. It might not be obvious on first
reading what should be grouped with what. For example,
The cat the dog the boy next door owns chases sleeps all day.
may only be resolved with some difficulty to a grouping like the following:
(
The cat
(
the dog
(
the boy next door owns
)
chases
)
sleeps all day
)
.
Knowing how the words in a phrase or sentence should be grouped together is not
the same thing as understanding what they mean (which is the subject of semantics).
In particular, there can be sentences of English that are syntactically well formed but
do not mean anything. Here is a famous example (due to Noam Chomsky):
Colorless green ideas sleep furiously.
The pattern and the grouping of these words are familiar even if the sentence is
odd semantically. Similarly, there can be meaningful groups of words that are odd
syntactically:
Accident car passenger hospital.
Even though this is not a well-formed sentence of English, one can still extract at least
part of its meaning.
8.1.1 Lexicon
The starting point for the syntactic analysis of a language is a
lexicon
. This specifies
the word categories of the language and the vocabulary in each category:
Articles:
a, the
Adjectives:
fat, rich, happy, oldest, orange,
...
Proper nouns:
Mary, John, Toronto, Great Britain,
...
Common nouns:
boy, sweater, park, milk, justice,
...
