c-command
In generative linguistics, specifically within syntax, c-command (short for "constituent-command") is a crucial structural relationship between nodes in a syntax tree. It is a necessary condition for many syntactic phenomena, including binding and quantifier scope.
A node A c-commands a node B if and only if:
- A does not dominate B, and B does not dominate A.
- The first branching node dominating A also dominates B.
In simpler terms, a node c-commands another node if it sits in the same "family tree" branch as it, without being above it, and the lowest node that contains the first node also contains the second. "First branching node" refers to the lowest node that has at least two daughters (nodes directly below it).
The concept of c-command is important because it restricts the possible relationships between constituents that are allowed to interact syntactically. For instance, a pronoun cannot be bound by a noun phrase that it c-commands. This restriction is one of the central tenets of binding theory. Similarly, the scope of a quantifier phrase is often limited by the domain it c-commands.
It is important to note that c-command is a hierarchical relation, determined solely by the structure of the syntactic tree. Linear order (the order in which words appear in the sentence) is not directly relevant to c-command.
Different theoretical frameworks within generative linguistics may have slightly different definitions or applications of c-command, but the core idea remains the same: to capture a specific type of structural relationship that is necessary for certain syntactic processes to occur.