In generative grammar and related frameworks, m-command is a syntactic relation between two nodes in a syntactic tree. A node m-commands a node if the maximal projection of dominates , but neither nor dominates the other.

In government and binding theory, m-command was used to define the central syntactic relation of government. However, it has been largely replaced by c-command in current research. M-command is a broader relation than c-command, since a node m-commands every node that it c-commands, as well as the specifier of the phrase that it heads. Like c-command, m-command is defined over constituency-based trees and plays no role in frameworks which adopt a different notion of syntactic structure.


  • Aoun, Joseph; Dominique Sportiche (1983). "On the Formal Theory of Government". Linguistic Review. 2: 211–236.
  • Chomsky, Noam (1986). Barriers. Cambridge, MA: MIT Press.