Morphophonemic Rule
A morphophonemic rule has the form of a phonological rule, but is restricted to a particular morphological environment.
Morphophonemic rules are sensitive to their environment, unlike phonological rules. Whenever morphological information is required to specify the environment for an allophonic rule, the rule is morphophonemic.
- The prefix /in-/ has the allomorphs [il] and [ir]
|
/in-/ + responsible |
irresponsible |
|
/in-/ + logical |
illogical |
The rules n G l / __l and n G r / __r are not phonological rules in English, however. If they were, the prefixes /un-/ and /non-/ would also exhibit this regular pattern, but they do not.
|
/un-/ + responsive |
(*urresponsive) |
unresponsive |
|
/un-/ + limited |
(*ullimited) |
unlimited |
|
/non-/ + retroactive |
(*nor-retroactive) |
non-retroactive |
|
/non-/ + lethal |
(*nol-lethal) |
non-lethal |
Therefore, there must be a morphophonemic rule which determines the allomorphs [il] and [ir] of the prefix /in-/.
This page is an extract from the LinguaLinks Library. Version 5.0 published on CD-ROM by SIL International, 2003.