:Lexical phonology:

A theory of phonology which stresses the importance of regularities in word-formation. One of the major concepts of lexical phonology is the recognition of two different types of phonological rule. These are (1) lexical rules and (2) post-lexical rules. Lexical rules have the following characteristics (amongst others):

  • they operate within words, but not across word boundaries
  • they are prone to exceptions
  • they need morphological information
  • they are not blocked by pauses

Post-lexical rules, on the other hand:

  • operate both within words and across word boundaries
  • are exception-free
  • need only syntactic information, or no grammatical information at all
  • may be blocked by pauses

For further information visit this page.