M-command


In theoretical linguistics, m-command is a syntactic relation between two elements in a tree structure. It is a broader version of c-command, and like c-command, it is defined over the constituency-based trees associated with the phrase structure grammars of the Chomskyan tradition ; it is therefore not applicable to the structures that other theories of syntax assume. For instance, it is not applicable to the dependency-based structures of dependency grammars. Aoun and Sportiche's definition of c-command in fact corresponds to what is now known as "m-command". Chomsky established the standard definition of m-command. If X and Y are two nodes in a syntactic tree, X m-commands Y if and only if:
The notion of maximal projection is adopted from X-bar theory. The difference between c-command and m-command is that X m-commands everything that it c-commands, and in addition, it m-commands the element in the specifier position of the phrase that it heads. M-command is used in the formulation of the syntactic relation government.