a1 Department of English, University of Hamburg
Allomorphy is a reaction of the morphological system to problems that the unrestrained application of inflectional and other rules creates at the phonological level. These problems are dealt with in some cases but left unattended in others. A diachronic analysis of English reveals that phonemically conditioned allomorphy originates from gradual sound change, with the old and the new variant forming a morphophonological paradigm. The historical stability as well as the synchronic motivation of allomorphy are claimed to be frequency-based. The higher the frequency, the longer the life expectancy. Synchronically, there is a (language- and domain-specific) frequency threshold above which morphophonological variation occurs and below which it fails to occur. The underlying logic of the model is that frequency encourages lexicalization at all linguistic levels. The relative ease with which high-frequency items are accessed enhances the tolerance towards formal variation, hence the emergence of natural phonological rules. As the application of these rules is context-dependent, allomorphy arises as a context-sensitive process. Repair strategies are also argued to be under the sway of frequency. Epenthesis is found in highly frequent structures while coalescence is reserved for less frequent ones. Frequency also determines the scope and the optionality of morphophonological rules. Phonemically governed allomorphy is shown to be a member of the larger family of variationist phenomena which are bound together by their sensitivity to frequency.
(Received June 16 2009)
(Revised February 15 2010)
(Online publication July 07 2010)
 A shortened version of this article was presented in the spring of 2009 at the Linguistic Colloquium of the University of Mainz, Germany, at which I benefited from Britta Mondorf's input. I owe a note of gratitude to Marion Neubauer and Christian Koops for performing the English frequency counts as well as to Arne Lohmann for showing me how to do it. I also thank Katerina Stathi, Florian Dolberg, Günter Radden and Craig Davis for their encouraging feedback on an earlier version as well as Nigel Isle for his allomorphic explorations in Nova Scotia. Luckily, I found in Marta Degani a helpful native speaker who provided me with highly welcome information on Italian. Above all, the two anonymous JL referees are to be credited not only for their truly excellent reviews but also for saving me from publicizing one of the most embarrassing scholarly blunders I have ever made.