1.3 Levels of meaning: word, sentence, and discourse

Levels of Meaning in Language

Language carries meaning at multiple scales. A single word has meaning, a sentence built from those words has meaning, and a stretch of connected sentences (discourse) has meaning shaped by context. This guide walks through each level and shows how they interact.

Levels of Linguistic Meaning

Word-level meaning is the domain of lexical semantics, which studies what individual words mean and how those meanings relate to each other.

• Words have denotative (literal) and connotative (associated) meanings.
  • Denotative meaning is the dictionary definition: bird denotes a warm-blooded, egg-laying vertebrate.
  • Connotative meaning is the emotional or cultural associations a word carries: bird might evoke freedom, nature, or fragility.
• Polysemy is when a single word has multiple related senses. Bank can mean a financial institution or the edge of a river.
• Words also stand in meaning relationships with each other: synonyms share similar meanings (happy / joyful), and antonyms have opposite meanings (hot / cold).

Sentence-level meaning is the domain of compositional semantics, which examines how word meanings combine based on grammatical structure.

• Syntactic structure determines the relationships between words, so changing the structure changes the meaning.
• Structural ambiguity arises when a sentence can be parsed in more than one way:
  • Prepositional phrase attachment: "I saw the man with the telescope" (Were you using the telescope, or did the man have it?)
  • Verb phrase attachment: "The chicken is ready to eat" (Is the chicken going to eat, or is it about to be eaten?)

Discourse-level meaning goes beyond individual sentences and considers the larger context of communication.

• Coherence (logical connections between ideas) and cohesion (linguistic devices like pronouns and conjunctions that tie text together) hold discourse together.
• Key phenomena at this level include implicature (implied meaning), presupposition (background assumptions), and speech acts (actions performed through utterances). Each of these is covered in more detail below.

Word Meaning in Sentences

The principle of compositionality states that the meaning of a sentence is determined by the meanings of its parts and the way those parts are combined. Words are the building blocks, and even swapping a single word can change the meaning entirely:

• "The cat chased the mouse" vs. "The mouse chased the cat" (same words, different structure, different meaning)
• "I love ice cream" vs. "I hate ice cream" (one word swap, opposite meaning)

Selectional restrictions are constraints on which words can meaningfully combine. "The table ate the sandwich" is grammatically fine but semantically odd because eat requires an animate subject. The verb selects for certain properties in its arguments.

Thematic roles describe the semantic function a word plays in a sentence:

• Agent: the doer of the action
• Patient/Theme: the entity affected by or undergoing the action

In "John kicked the ball," John is the agent and ball is the patient. Recognizing thematic roles helps you see why "The ball kicked John" means something very different even though it uses the same words.

Sentence Meaning and Structure

Syntactic structure does real work in determining meaning. "The dog bit the man" and "The man bit the dog" contain identical words, but their different structures assign different thematic roles, producing different meanings.

Structural ambiguity (covered briefly above) is worth looking at more closely because it shows up constantly in natural language:

• Prepositional phrase attachment: "I saw the man with the telescope" has two parses depending on whether with the telescope modifies saw or the man.
• Verb phrase attachment: "The chicken is ready to eat" is ambiguous about whether the chicken is the eater or the thing being eaten.

Scope ambiguity is a different kind of ambiguity that arises from quantifiers and logical operators. Consider:

This sentence has two readings:

1. $\forall x \, \exists y$: For every boy, there is some girl he loves (possibly a different girl for each boy).
2. $\exists y \, \forall x$: There is one particular girl that every boy loves.

The sentence is identical on the surface, but the two logical forms assign different scope to the quantifiers every and some. This is a core topic in formal semantics.

Compositionality is powerful: because meaning is built up systematically from parts, speakers can produce and understand an infinite number of novel sentences from a finite vocabulary.

Discourse Context in Interpretation

Discourse context includes the surrounding text, the physical situation, and the shared knowledge between speaker and listener. It plays several critical roles:

Disambiguation. Context resolves ambiguity that sentence-level analysis alone cannot. If someone says "I went to the bank" while holding a fishing rod, you interpret bank as a riverbank, not a financial institution.

Anaphora resolution. Pronouns and other referring expressions get their meaning from context. In "John took his dog for a walk. He loves spending time outdoors," he refers back to John. You resolve this through discourse context, not sentence grammar alone.

Implicature is meaning that's implied but not explicitly stated. There are two main types:

• Conversational implicature arises from the assumption that speakers are being cooperative. "Can you pass the salt?" is literally a question about ability, but in context it functions as a request. The listener infers the intended meaning because a bare question about salt-passing ability would be uncooperative.
• Conventional implicature is meaning built into certain words or constructions. "He is a lawyer, but he is honest" uses but to signal a contrast, implying that honesty is unexpected for lawyers. That implication comes from the word but itself, not from the conversational situation.

Presupposition refers to background information that a sentence takes for granted. "John stopped smoking" presupposes that John used to smoke. If John never smoked, the sentence isn't just false; it feels like a misfire because its presupposition fails.

Speech acts are the actions we perform through utterances. Saying "I promise to help you tomorrow" doesn't just describe a promise; it makes one. "Could you close the window?" has the grammatical form of a question but functions as a polite request. Speech act theory (developed by Austin and Searle) analyzes how utterances do things in the world, not just say things about it.