Post on 27-Nov-2021
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Semanticshttp://www.etymonline.com
Science of meaning in language
Greek semantikos sema "sign”
ics : a suffix of nouns that denote a body of facts, knowledge, principles
e.g.) ethics, physics, politics
What is Semantics?
The study of the linguistic meaning of
morphemes, words, phrases, and sentences
Subfields
Lexical Semantics: the meanings of words
Phrasal/Sentential Semantics: the meaning of
syntactic units larger than the word
Pragmatics: The study of how context affect
meaning e.g.) It’s cold in here.
Sentential meaning
entailment
tautology vs. contradiction
Compositional Semantics
Anomaly vs. metaphor vs. idioms
Lexical Semantics
Sense vs. reference
Lexical relations
Semantic features
Argument structure: Thematic roles
Speakers’ knowledge of meaning includes
The truth conditions of sentences
when one sentence entails another
When two sentences are paraphrases
or contradictory
When a sentence is a tautology,
contradiction or paradox
When sentences are ambiguous
Truth-conditional/compositional Semantics
Truth conditions: Most sentences are true or
false in a given situation
STNs that are always true
Tautologies/analytic
STNs that are always false
=> Contradictions
Truth-conditional/compositional Semantics
Circles are round. A bachelor is single.
=> Tautologies
Circles are square. A bachelor is married.
=> Contradictions
Cf) All students are liars. (A student says this)
=> paradoxes
Entailment and Related Notions
1) Entailment holds the meaning relation
between sentences (propositions);
A entails B if whenever A is true B is also
true, in all conceivable circumstances
e.g. Jack swims beautifully (A) entails
Jack swims (B).
Entailment vs. synonymy
2) Two sentences ______________
(paraphrases) if they entail each other.
e.g. Jack put off the meeting.
= Jack postponed the meeting.
synonymous
Entailment vs. contradiction
3) Two sentences are ______________
if one entails the negation of the other.
Two sentences are contradictory if,
whenever A is true, B is false.
e.g. ‘Jack is alive’
‘Jack is dead’ (=Jack is not alive)
contradictory
Ambiguity with PS trees
e.g. The boy saw the man with the telescope.
S S
NP VP NP VP
VP PP V NP
The boy saw the man with the telescope The boy saw NP PP
the man with the telescope
SEMANTIC AMBIGUITY
Semantic ambiguity results from different
PS structures.
=> Principle of Compositionality: the
meaning of a sentence is composed of the
meanings of its parts(words/expressions)
and how they are combined structurally.
Compositional Semantics
What is the meaning of the sentence Jack swims?
a) Word Meanings:
Jack - refers to the individual Jack.
Swims - refers to the set of individuals that swim
b) Syntactic Structure S
NP VP
Jack swims
Entailment & Rules
‘Jack swims beautifully’
Any truth condition that causes Jack
swims beautifully (A)to be true
necessarily causes Jack swims (B) to
be true, hence A entails B.
Counterexamples to Compositionality
1) Anomaly
a) semantic violations
Colorless green ideas sleep furiously.
[without color] + [green in color]
b) Semantic violations in poetry=> metaphor
a week ago [temporal semantic feature] vs.
a grief ago [an unhappy time after a sad event]
Counterexamples to Compositionality
2) Metaphor (<= anomaly)
a) literal & metaphorical meanings => ambiguity
b) Accommodate meaning w/ semantic properties
e.g. Walls have ears.
c) the word meaning + facts about the world.
e.g. Time is money.
d) cultural components: a bug in my program.
e) Relate to language creativity and change
e.g. the fall of the dollar
Counterexamples to Compositionality
3) Idioms/Idiomatic phrases (<= metaphor)
a) Idioms have fixed meanings (not compositional)
b) Idioms are frozen in form
e.g. She put her foot in her mouth.
?Her foot was put in her mouth.
c) Idioms violate semantic restriction
e.g. He ate his hat.
d) Idioms are stored as single items in the lexicon
LEXICAL SEMANTICS
Theories of Word Meaning
1) referent: The meaning of a word is its reference,
its association with the object it refers to.
a) The NP refers to the individual Jack.
e.g. Jack swims.
b) Not every NP refers to an individual.
e.g. No baby swims.
c) Two different NPs with the same referent.
e.g. Barack H. Obama vs. the president of the U.S.
Theories of Word Meaning
2) Sense: the way we think about an expression
a) The president: ‘the head of the state’
cf) ROH, Moo-hyun / LEE, Myungbak
b) Proper names have sense but no reference
e.g.) Harry Potter
3. 2 Lexical Relations
1) Synonyms: different words w/ similar meaning
a) No perfect synonyms e.g. sofa vs. couch
b) Many French loanwords: manly vs. virile
2) Antonyms: words that are opposite in meaning
a) Complementary pair: alive/dead (not A = B)
b) Gradable pair: big/small (not A ≠ B)
c) Relational opposites: teacher vs. student
cf) autoantonyms: cleave
3) different words/same pronunciation
a) ambiguity: I’ll meet you by the bank
b) humor/confusion: flour vs. flower
bare and bear are __________ (also called
___________) which are words that have
different meanings but are pronounced the
same, and may or may not be spelled the
same. They are _____________ when spelled
the same as in bow but called ___________
when pronounced differently as in pussy.
homonyms
homophones
homographs
heteronyms
4) Polysemy: multiple meanings with a conceptual
or historical link
bear1: i) tolerate ii) carry iii) support
bear2: a large strong animal with thick fur
bare: i) without clothes ii) not covered/empty
=> bear1 and bare are ______________, while
bear1, bear2, bare are ___________.
polysemous
homonyms
5) Hyponyms: specific instances of a general word
e.g. red, white, blue /color
- X is a hyponym of Y; Y has the hyponym X
=> Y is a hypernym of X
Y (general category)
X (specific components)
3. 3. Semantic Features
a formal device indicating the presence or
absence of semantic properties
tigress, doe, ewe, hen, mare
aunt, debutante, girl, maiden, widow
father, uncle, bachelor
bring, fall, plod, walk, run, …
hit, kiss, touch, …
see, hear, feel
+ animate – animate vs. + human - human
+female
+human +female
+human –female
+motion
+contact
+sense
Semantic Features of Nouns
Decomposing into semantic features
woman father girl cock rice
+count + count +count + count -count
+human +human +human -human -human
+female -female +female -female . . .
-young -young +young . . . . . .
. . . . . . . . . . . . . . .
*He has two rices.He has a cock. vs.
Semantic Features of Verbs
i) Verbs can be broken down into semantic
features.
darken cause to become dark.
kill cause to die
uglify cause to become ugly
=> [cause]
Semantic Features of Verbs
ii) eventive vs. stative distinction
EVENTIVES
Mary was kissed by John.
John is kissing Mary.
Kiss Mary!
John deliberately kissed Mary.
Semantic Features of Verbs
ii) eventive vs. stative distinction
STATIVES
?Mary was known by John.
?John is knowing Mary.
?Know Mary!
?John deliberately know Mary.
Semantic Features of Verbs
iii) Negation: Negative polarity item – NPI
John thinks that he’ll ever fly a plane anymore.
John doesn’t think that he’ll ever fly a plane anymore.
John hopes that he’ll ever fly a plane anymore.
John doubts that he’ll ever fly a plane anymore.
John despairs that he’ll ever fly a plane anymore.
Semantic Features of Verbs
iii) Negation: Negative polarity item – NPI
*J thinks that he’ll ever fly a plane anymore.
J doesn’t think that he’ll ever fly a plane anymore.
*J hopes that he’ll ever fly a plane anymore.
J doubts [think that not] that he’ll ever fly a plane anymore.
J despairs [has no hope] that he’ll ever fly a plane anymore.
ARGUMENT STRUCTURE
a) C-selection
i) The various NPs occurring w/ a verb: arguments
Intransitive verbs have one argument: S
Transitive verbs have two arguments: S O
Di-transitive verbs have three arguments: S IO DO
ii) The argument structure of a verb is part of its
meaning AND included in its lexical entry.
ARGUMENT STRUCTURE
b) S-selection
the verb limits the semantic properties of
both its subject and its complements
Colorless green ideas sleep furiously
[sleep s-select animate subjects]
Our knowledge of verbs include
their syntactic category
which objects they select;
the thematic roles that their NP
subject and object(s) have.
THEMATIC ROLES
¶ agent: the doer of the action
¶ theme: the undergoer of the action
¶ goal: the endpoint of a change in location or
possession
¶ source: where the action originates
¶ instrument: the means used to accomplish
the action
¶ experiencer: one receiving sensory input
THEMATIC ROLES
The boy found a red brick.(agent) (theme)
The boy threw the red ball to the girl.(agent) (theme) (goal)
The boy bought the red ball from John.(agent) (theme) (source)
The boy opened the door with the key.(agent) (theme) (instrument)
THEMATIC ROLES
The boy saw the man with a telescope (experiencer) (theme) (instrument)
The boy hit the man with a ball.(agent) (theme) (instrument)
THE SAME THEMATIC ROLES
The dog bit the stick.(agent) (theme)
The stick was bitten by the dog(theme) (agent)
The trainer gave the dog a treat(agent) (goal) (theme)
The trainer gave a treat to the dog.(agent) (theme) (goal)