Semantics 2: Syntax-Semantics Interface

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Semantics 2 Syntax-Semantics Interface

• Ling400

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Sentence Meaningand Truth Conditions

• It is not easy to say what a sentence means.
• The meaning of sentence S can be thought of as
  the truth conditions for S
• George W. Bush is in the White House.
• If you know its meaning, then you know how to go
  about checking its truth conditions, and vice
  versa.

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Principle of Compositionality

• Idea You know the meaning of a complex
  expression (including sentences) because you know
  the meanings of its parts (words).
• You somehow put together word meanings to get
  to the meaning of the whole, and this process
  relies on the syntactic structure.

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Our assumptions so far

• proper name --gt the object it denotes
• common noun --gt the set of all things that have
  the property/quality in question
• What about verbs?

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Assume that VP denotesa collection (set) of
things

• Intransitive verbs (and all other VPs) denote
  (mean) collections (sets) of things.
• E.g. sings means/denotes
• (the set of) those who sing

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Truth conditions of a simple sentence

• John sings is true just in case
• the individual John is an element of the
• collection (set) of those who sing.

John must be in there somewhere.
Sentence of the form NP VP is true just in case
the meaning of NP is an element of the meaning of
VP.
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VP conjunction (VP and VP)

• VP
• VP conj VP
• sings and dances means

intersection
Mary sings and dances is true just in case
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VP disjunction (VP or VP)
VP VP conj VP sings or
dances means

Intersection is optional
union (the whole thing)
Mary sings or dances is true just in case
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Two meanings of or?

• Some say that or has an inclusive meaning
  (represented by union taking the whole thing
  including the overlap (intersection))
• Others say that or has an exclusive meaning
  (i.e., A or B and not both)
• For our purpose of exposition, we adopt the
  latter.

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Counterfactuals

• If kangaroos had no tails, they would topple
  over.
• If Oswald had not killed Kennedy, someone else
  would have.
• Truth conditions Assume that the antecedent is
  true. Otherwise, the hypothetical situation is
  almost the same as the real world. On these
  assumptions, the consequent (main clause) is true.

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Sentences with Quantifiers
cats

• Every dog barks.
• No cat laughs.

no overlap
dogs
Dogs are completely contained in those that bark.
those who laugh
barks
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Sentences with Quantifiers
cats

• Every dog barks.
• No cat laughs.

dogs
This means that some dogs do not bark.
those who laugh
This means that some cats laugh.
barks
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