What is a feeding relationship between rules?

A feeding relationship occurs when one rule creates the conditions under which a later rule can apply, so the first rule increases the number of forms the second rule affects.

What is opacity in phonology?

Opacity occurs when a rule's application is not transparently reflected on the surface, either because a rule applies although its trigger is no longer visible, or fails to apply although its context appears present.

Rule Ordering and Derivations

In rule-based phonology, multiple rules apply in sequence to derive a surface form, and the order in which they apply can determine the outcome.

Definition

The principle that phonological rules apply in a specified sequence to derive surface forms, together with the patterns of interaction such as feeding and bleeding.

Scope

This topic covers the derivational architecture of classical generative phonology: how an underlying form passes through a series of ordered rules to yield the surface form. It treats the typology of rule interactions—feeding and bleeding, and their counterfactual counterparts—and the arguments that rule order must be specified rather than free. It also covers opacity, where the effect of a rule is not transparently visible on the surface, which became a key issue motivating and challenging later theories. The treatment is descriptive and analytic.

Core questions

Why must phonological rules sometimes be ordered?
What are feeding and bleeding interactions?
What is rule opacity and why does it matter?
How does a derivation proceed from underlying to surface form?

Key theories

Extrinsic rule ordering: The claim of classical generative phonology that the grammar specifies a fixed order in which rules apply, accounting for feeding and bleeding interactions that free application could not predict.

History

Rule ordering was a central concern of generative phonology after 1968, with extensive work by Kiparsky and others on the typology of interactions and on principles such as the elsewhere condition. Opacity in particular became a touchstone in evaluating rule-based and later constraint-based theories.

Debates

Handling opacity: Opaque interactions, where a rule applies even though its triggering context is no longer present on the surface, are naturally captured by ordered rules but pose difficulties for purely output-oriented constraint theories, fueling ongoing debate.

Key figures

Noam Chomsky
Morris Halle
Paul Kiparsky
Michael Kenstowicz

Seminal works

chomsky1968
kenstowicz1994

Frequently asked questions

What is a feeding relationship between rules?: A feeding relationship occurs when one rule creates the conditions under which a later rule can apply, so the first rule increases the number of forms the second rule affects.
What is opacity in phonology?: Opacity occurs when a rule's application is not transparently reflected on the surface, either because a rule applies although its trigger is no longer visible, or fails to apply although its context appears present.