---
title: "C-Command — Intro to Semantics & Pragmatics Definition"
description: "C-command is a structural relation between nodes in a syntax tree that controls binding, telling you when a pronoun or reflexive can corefer with another phrase."
canonical: "https://fiveable.me/introduction-semantics-pragmatics/key-terms/c-command"
type: "key-term"
subject: "Intro to Semantics and Pragmatics"
unit: "Unit 11"
---

# C-Command — Intro to Semantics & Pragmatics Definition

## Definition

C-command is a syntactic relationship in a tree where one node c-commands another if the first node's sister (or a node it dominates) contains the second node. In semantics and pragmatics, it sets the structural conditions for binding and coreference.

## What It Is

C-command describes a relationship between two nodes in a sentence's tree structure. A node A c-commands a node B if A does not dominate B, B does not dominate A, and the first branching node above A also contains B. A simpler way to picture it: A c-commands its sister node and everything inside that sister.

This is a structural idea, but in this course you care about it because of what it does for meaning. C-command is the backbone of binding theory, which decides when a pronoun or reflexive can refer to the same entity as another phrase. In *John saw himself*, the NP *John* c-commands *himself*, so the reflexive can be bound and the sentence means John saw John. When the c-command relation isn't there, that interpretation breaks down. So a piece of syntactic geometry ends up controlling who refers to whom.

## Why It Matters

C-command lives in Topic 11.2, binding theory and constraints on coreference. The whole point of that topic is showing that reference is not free: syntactic structure constrains which noun phrases can corefer. Binding theory's three principles (for anaphors, pronouns, and R-expressions) are all stated in terms of c-command, so you can't apply the principles without it.

For a semantics and pragmatics course, this matters because it links structure to interpretation. Understanding c-command lets you predict and explain why *himself* must point back to a local subject, why some pronoun readings are blocked, and how ambiguity gets resolved. It's a clean example of syntax doing semantic work.

## Connections

### Binding Theory (Unit 11)

Every binding principle is defined using c-command, so c-command is the tool that decides when an anaphor or pronoun is bound. Learn one and the other immediately makes more sense.

### Dominance (Unit 11)

C-command is defined partly by what a node does NOT dominate. Knowing dominance (a node containing another) lets you state the c-command condition precisely.

### Coreference (Unit 11)

C-command is what licenses or blocks coreference between two NPs. Two phrases can name the same entity only when the structural relation allows it.

### [Syntactic hierarchy (Unit 11)](/introduction-semantics-pragmatics/key-terms/syntactic-hierarchy)

C-command only makes sense inside a hierarchical tree, since it depends on which node sits above which. The whole notion comes from how sentences are layered structurally.

## On the AP Exam

Expect to draw or read a tree and decide whether one node c-commands another, then use that to predict whether a reflexive or pronoun reading is grammatical. Problem sets often give sentences like *John saw himself* versus a version where binding fails, and ask you to justify the difference using c-command. On quizzes and short-answer questions you may need to state the c-command definition and apply a binding principle to a specific NP. In essay or analysis tasks, you'll use c-command to explain why certain coreference interpretations are blocked or required.

## c-command vs Dominance

Dominance is a vertical relation: node A dominates B if A is above B and contains it on the same path. C-command is more sideways: A c-commands its sister and everything inside the sister, and crucially A does NOT dominate what it c-commands. Many binding errors come from mixing these two up.

## Key Takeaways

- A node c-commands its sister node and everything contained inside that sister.
- C-command requires that neither node dominates the other, which is what separates it from dominance.
- Binding theory's principles for anaphors, pronouns, and R-expressions are all stated in terms of c-command.
- In *John saw himself*, *John* c-commands *himself*, which is why the reflexive can be bound and the sentence is grammatical.
- C-command is a syntactic relation that has direct consequences for meaning by constraining coreference.

## FAQs

### What is c-command in semantics?

C-command is a structural relation in a syntax tree where one node c-commands its sister node and everything inside that sister. It matters in semantics because binding theory uses it to decide when a pronoun or reflexive can refer to the same entity as another noun phrase.

### Is c-command the same as dominance?

No. Dominance is vertical: a node dominates another node it contains directly above it. C-command is defined so that a node does NOT dominate what it c-commands; instead it reaches its sister and the sister's contents.

### Why does c-command matter for reflexives like himself?

Reflexives are anaphors that must be bound by a c-commanding antecedent in their local domain. In *John saw himself*, *John* c-commands *himself*, so binding succeeds; without that c-command relation, the reflexive would be ungrammatical.

### How do I tell if one node c-commands another in a tree?

Find the first branching node above the node you're testing. If the other node is inside that branch (and neither node dominates the other), the first node c-commands it.

### Does c-command alone decide coreference?

Not by itself. C-command sets the structural condition, but binding theory's principles plus the type of NP (anaphor, pronoun, or R-expression) together determine whether coreference is allowed.

## Related Study Guides

- [11.2 Binding theory and constraints on coreference](/introduction-semantics-pragmatics/unit-11/binding-theory-constraints-coreference/study-guide/gBcjWhXXFvCHUFGO)

## About This Document

Canonical Fiveable pages are available as Markdown at the same path plus `.md`.

- [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns
- [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing
- [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`)
- [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`)

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