Semantic Boston University

Your dog ate my homework. What does this sentence mean? Is it true? What is the current status of my homework? What was the prior status of my homework? Your dog will have eaten my homework. Your dog must have eaten my homework. Your dog might have eaten my homework.

Levels of linguistic knowledge Native speakers have a complex system of knowledge. Phonology Morphology Syntax Semantics … Our goal is to understand and characterize this complex system.

Some data our theory should account for Linguistic expressions have actual meanings The English sentence Camels have humps means that camels have humps. The French sentence Les chameaux ont des bosses means that camels have humps. The English sentence Camels have humps does not mean that reptiles have wings.

Some data our theory should account for Linguistic expressions can be ambiguous. The English sentence Pedro jumped from the top of the bank has two meanings. The English sentence Mad dogs and Englishmen go out in the noonday sun has two meanings. The English sentence John saw her duck has two meanings.

Some data our theory should account for Some linguistic expressions are felt to be anomalous. Colorless green ideas sleep furiously. My toothbrush is pregnant. Hammers frighten rocks.

Some data our theory should account for These are true in the same situations (synonymous): The wug is under the pim. The pim is above the wug. And not in this one (contradiction): The wug is not under the pim. At least two distinct kinds of situations make this true: Every wug is under three pims. And this must also be true of the same kind of situation: Every wug is under two pims.

Some data our theory should account for Boris ate an apple. Boris ate. Boris is too clever to catch Rocky. Boris is too clever to catch.

Productivity We can know what a sentence means even if we haven’t heard that sentence before. If we knew what a wug and a pim were, we would know what the sentence The pim is under the wug would mean. There must be an algorithm for figuring out what a sentence means (like the algorithm for adding two novel numbers).

Productivity We can create novel meaningful sentences. S1 and S2 is a sentence where S1 and S2 are sentences (and S1 and S2 is true when both S1 and S2 are true). Sa = Pat left Sb = Tracy cried Sc = Chris ate a sandwich S1 = Sa and Sb = Pat left and Tracy cried S2 = S1 and Sc = Pat left and Tracy cried and Chris ate a sandwich

Compositionality In order to be able to do this is must be the case that meaning is compositional. That is: The meaning of the whole is determined by the meaning of the parts and how those parts are arranged.

A noble spirit embiggens the smallest man Fax, refax, faxer, refaxer, unrefaxeristic. Unzippable [Un-zip]-able (able to be unzipped) Un-[zip-able] (unable to be zipped)

Connecting to the world We use language to talk about things. There is some kind of connection to the world outside of language. For example, we can use names and noun phrases to refer to individuals. We use Pat to refer to Pat the individual; Pat denotes Pat the individual.

Connecting to the world Truth and falsity is something like this as well. Whether a sentence is true or false depends on The actual meaning of the sentence How things are in the outside world

Levels of description We can talk about language from a number of different perspectives. An utterance is a piece of language, created, e.g., by speaking or writing. A sentence is an abstract arrangement of words. Two people can say the same sentence (resulting in two different utterances). A proposition is “a complete thought.” The sentences Pat ate the sandwich and The sandwich was eaten by Pat express the same proposition. One is true if and only if the other is true.

Propositions A proposition can be true or false, depending on the situation it is being considered with respect to. A proposition is generally a combination of a predicate (a verb or a property) and one or more arguments (referential expressions). grilled (Pat, the sandwich) Propositions can often be expressed in more than one way (Pat grilled the sandwich, The sandwich was grilled by Pat), so they are more abstract than sentences.

Language in context Sentences can be said to have a literal and, sometimes, a non-literal meaning. My feet are killing me. Literally false, but the speaker presumably intended to communicate something, so we must work out what it is.

Language in context When we speak of semantics, we are generally speaking of meaning abstracted away from speakers and individual utterances. The context-independent meaning. When we speak of pragmatics, we are speaking of language use and language users. The motivations for using a particular sentence. Could you pass the salt? It’s getting late. I have two children. Mr. Stevens’ command of English is excellent, and his attendance at class has been regular.

Mental models Prince Charles is British. This is true. There’s a property, to be British, that holds of the guy in the world that Prince Charles denotes. James Bond is British. This is also true. But who is the property to be British true of?

Mental models We can talk about much more than just the real world as it actually is. If Prince Charles is not British, I will eat my hat. Imagine a world much like ours, but in which the guy Prince Charles denotes does not possess the property to be British. In that world, I will also eat my hat (if the entire proposition is true). Last night I dreamt I was Prince Charles.

Mental models Denotation and properties seem to be evaluated against a model of the world, which may—but need not—correspond to how the world actually is. We can shift between models easily, to talk about fiction, to talk about (possibly mistaken) beliefs, to talk about wishes, dreams. The most coherent way to think about what names like James Bond denote is to take them to denote individuals in a mental model, where the model might (or might not) be one corresponding to the real world.

Object language and metalanguage In order to accurately describe the meaning of a word, sentence, morpheme, etc., we need a language in which to couch our description. If we try to describe the meaning of English in English, we run into trouble with circularity. Instead, we will often work with a formal metalanguage, with which we can describe the meanings and meaning relations in English and in other languages equally. Les chameaux ont des bosses is true if and only if camels have humps. January has 31 days. January has 7 letters.

For communication to work, the interlocutors must share this intricate semantic knowledge—everybody (speaking the same language) ends up at the same state of knowledge.