C-command

In syntax, c-command is a relationship between nodes in parse trees. Originally defined by Tanya Reinhart (1976, 1983), [See also Howard Lasnik (1975) and Noam Chomsky (1981).] it corresponds to the idea of "siblings and all their descendants" in family trees.

Definition and Example

The definition of c-command is based partly on the relationship of "dominance". A node "dominates" another node if it is above it in the tree (it is a parent, grandparent, etc.)

Using this definition of dominance, A node "A" c-commands a node "B" if and only if:
*A does not dominate B
*B does not dominate A
*Every branching node that dominates A, also dominates Bcite book
last = Haegeman
first = Liliane
title = Introduction to Government and Binding Theory
page = 147
edition = 2nd ed.
publisher = Blackwell Publishing
location = Oxford
year = 1994] cite book
last = Carnie
first = Andrew
title = Syntax: A Generative Introduction
page = 75
edition = 1st ed.
publisher = Blackwell Publishing
location = Oxford
year = 2002]

For example, in the following tree:
* "A" c-commands "C", "D", and "E".
* "B" does not c-command any nodes.
* "C" c-commands "A".
* "D" c-commands "E".
* "E" c-commands "D".

B / A C / D E

Origin of term

"C-command" is generally taken to be a shortened form of "constituent command." According to anonymous sources cited by Andrew Carnie,cite book
last = Carnie
first = Andrew
title = Syntax: A Generative Introduction
page = 77
edition = 1st ed.
publisher = Blackwell Publishing
location = Oxford
year = 2002] however, the etymology of "c-command" may also be traced back to a time in the 1970s when the c-command relationship existed alongside another relationship, "kommand", proposed by Howard Lasnik in 1976.cite web
url = http://web.mit.edu/ekeshet/www/Papers/phase.pdf
last = Keshet
first = Ezra
title = 24.952 Syntax Squib
publisher = MIT
date = 2004-05-20] Since "command" and "kommand" were pronounced the same way, linguists may have differentiated them by referring to them as "c-command" and "k-command," respectively. It is unclear, then, whether the term "c-command" is left over from this former distinction, or "constituent command" was a pre-existing term and "c-command" an abbreviated form of it.

C-command and the first branching node

The above definition specified that the domain of c-command is the first "branching" node that dominates A. This relationship is sometimes known as "strict c-command".cite book
last = Haegeman
first = Liliane
title = Introduction to Government and Binding Theory
page = 137
edition = 2nd ed.
publisher = Blackwell Publishing
location = Oxford
year = 1994] Without this specification, c-command would be limited to cases in which the first node of any sort dominating A also dominates B. The following tree illustrates how these two accounts differ in their result. If all nodes are considered, then "A" does not c-command any other nodes, because "B" dominates it and does not dominate any other nodes; if only branching nodes are considered, then "B" is irrelevant in evaluating the third criterion, and "A" does c-command "D", "E", and "F".

C / B D
| A E F

References

* http://www.criticism.com/linguistics/govt-binding-basics1.php
* Harris, C. L. and Bates, E. A. (2002) 'Clausal backgrounding and pronominal reference: A functionalist approach to c-command'. "Language and Cognitive Processes" 17(3):237-269.
* "Contemporary Linguistics" by William O'Grady, Michael Dobrovolsky, and Mark Aronoff. Bedford/St. Martin's. 1997 (third edition).

ee also

*m-command

External links

* [http://www.ling.upenn.edu/courses/Fall_1999/ling550/ch1.html c-command and pronouns]
* [http://www.ling.upenn.edu/~beatrice/syntax-textbook/box-nodes.html node relations; Penn University]