5.3 Sentential Semantics
• Apart from parts of speech ( eg. N, V, Adj, Adv )
that are used to syntactically categorized a
particular element of a clause or sentence, a
certain element in a sentence can also be
described semantically in terms of semantic
categories, called “ thematic roles”
Thematic Roles
• The relations of noun phrase subject of the sentence depend
on the meaning of particular verb.
• For example
• The boy found a red brick
• NP “ the boy “ called “agent”
• The boy is a “ doer” of the action of finding
• The boy found a red brick
•The NP “a red brick” is the “theme” and
undergoes the action
• Part of the meaning “ find” is that its subject and
direct object
• Subject of find is called “ agent”
• Direct object of find is called “ theme”
Goal
• The noun phrases within a verb phrase whose head is
the verb PUT have a relation of theme and GOAL.
• In the VP “ put the red brick on the wall”
• The red brick is a theme and on the wall is GOAL
Other thematic roles
Thematic role description example
Agent The one who performs an action Joyce ran
Theme The one or thing that undergoes an action Mary called Bill
Location The place where an action takes place It rains in Spain
Goal The place where an action is directed Put the cat on the porch
Source The place from which an action originates He flew from Iowa to Idaho
Instrument The meaning by which an action is performed Jo cuts hair with razor
Experiencer One who perceives something Helen heard Robert play the
piano
Causative A natural force that causes a change The wind damage the roof
Possessor One who has something The tail of the dog got caught in
the door.
• Thematic roles are the same in sentence that are
paraphrases. In these both sentences
• The dog bit the stick
• The stick was bitten by the dog
The dog is the agent and the stick is the theme
The examples illustrate the fact that English
allows many different thematic roles.
•The hotel forbids dogs.
The hotel has the thematic role of location
The Theta-Criterion
• A universal principle has been proposed call the Theta-criterion,
a particular thematic role may occur only once in a
sentence.
• For example ;
• The boy opened the door with the key with lock-pick.
Sentential Meaning
• The meaning of the sentences is built. In part, from
meaning of noun phrases and verb phrases. Adverbs
may add to or qualify the meaning.
• For example;
• The boy found the ball yesterday “ adv. Of time”
• It specify a time component to the meaning of the
sentence.
The truth of sentences
• The sense of a declarative sentence permits you to know
under what circumstances that sentence is true. Those
“circumstance” are called the TRUTH condition of the
sentence.
For example
In the world as we know it, the sentence;
The declaration of Independence was signed in 1776 “ true”
The declaration of Independence was signed in 1976 “ false”
We compare the with the real world or historical fact
Paraphrase
• Two sentences are phrases if they have the same truth
conditions.
• For example
• The horse threw the rider
• The rider was thrown by the horse
Entailment
• Sometimes knowing the truth of one sentence entails or
necessarily implies the truth of another sentence. For
example;
• Corday assassinated Marat
• Then we know that it is true that Marat is dead.
Contradiction
Contradiction is negative entailment, that is, where the
truth of one sematic necessarily implies the falseness of
another sentence.
Elizabeth II is Queen of England.
Elizabeth II is a man.
If the first sentence is true, the second is necessarily
false. This relationship is called CONTRADICTION
because the truth of one sentence contradicts the truth
of the other.
When semantics and syntax meet
• Syntax is concerned with how words are combined to form
phrases and sentences; semantics is concerned with what
these combinations mean. The theta-criterion. The semantic
constraint that no thematic role may occur more than once
has the effect of restricting the NPs and PPs that may follow
the verb in a verb phrase.
When Passive Do Not Work
• The relationship between actives and passives is
based on syntax structure. However, some active
sentences do not have a well-formed passive
counterpart.
For example;
• John resembles Bill
• The book cost ten dollars
• Cannot undergo the passive transformation to give
• “ Bill was resembled by John “
• “Ten dollars was cost by the book”
Pronouns and Coreferentiality
• Another example of how syntax and semantic interact has to
do with reflexive pronouns, such as herself or themselves.
The meaning of a reflexive pronouns always refers back to
some antecedent. In Jane bit herself, herself refers to Jane.
Syntactically, reflexive pronouns and their antecedents must
occur within the same S in the phrase structure tree.
Compare the phrase structure tree of
Jane bit herself with that of
Jane said that herself slept.
• S S
NP VP NP VP
Jane V NP Jane V NP
bit pronoun said that S
herself NP VP
pronoun V
herself slept
When rules are broken
• The rules of language are not laws of nature. Only by a
“miracle” can the law of nature be broken, but the rules of
language are broken every day by everybody.
3 kinds of rule violation
•Anomaly
•Metaphor
•idioms
Anomaly: No sense and Nonsense
• Don’t tell me of a man’s being able to talk sense;
everyone can talk sense.
Can he talk nonsense?
William Pitt
For example;
• My brother is an only child.
• You might think that he was making a joke or that he
did not know the meaning of the words he was using.
It is strange or anomalous, but it is certainly an English
sentence. It conforms to all the grammatical rules of
the language.
Uninterpretable
• Other English sentences make no sense at all because they
include words that have no meaning.
• Jabberwocky is probably the most famous poem in which
most content words have no meaning. They do not exist in the
lexicon of the grammar.
Metaphor
• Sometimes the breaking of semantic rules can be used convey
a particular idea.
• Wall have ears
• It is a certainly anomalous, but it can interpreted as meaning
• “ you can be overheard even when you think nobody is
listening.
Idioms
• Knowing a language includes knowing the
morphemes, simple words, compound words, and
their meanings. In addition it means knowing fixed
phrases, consisting of more than one word, with
meaning that cannot be inferred from the meanings of
the individual words. The usual semantic rules for
combining meanings do not apply. Such expressions
are called “IDIOMS”
Idioms
• For example
• Sell down the river
• Eat my hat
• Let their hair down
• Cut it out
• Many Idioms may have originated as metaphorical
expressions that established themselves in the language and
became frozen in their form and meaning.