Coronal stop deletion (or‚`TD Deletion‚`) is the paradigm sociolinguistic variable. It was first described in African American English (Labov et al., 1968) as a rule whereby word final /Ct/ and /Cd/ clusters simplify by deleting the coronal stop. It has since been found in many dialects and varieties of English. Aside from the very regular phonological and phonetic factors which condition whether TD Deletion applies, morphological structure also appears to have an effect. The three morphological categories of primary interest are (i) monomorphemes}, (ii) regular past tense verbs and (iii) semiweak past tense verbs.
In almost every dialect studied, the order of morphological classes from least favoring deletion to most favoring deletion is as given in (1).
(1) monomorphemes > semiweak > regular past tense
In this paper, I will be focusing on the difference between semiweak and regular past tense. I will pursue a revised version of the analysis in Guy & Boyd (1990), casting it in terms of Competing Grammars and Distributed Morphology. Specifically, I will propose that the rate of phonological TD Deletion is the same for the regular past and the semiweak. What leads to higher TD Absence in the semiweak verbs is variable morphological absence of /t/, i.e., there is a competing morphological analysis where the past tense of keep is simply "kep", instead of "kept".
Fruehwald, Josef T.
"Redevelopment of a Morphological Class,"
University of Pennsylvania Working Papers in Linguistics: Vol. 18:
1, Article 10.
Available at: https://repository.upenn.edu/pwpl/vol18/iss1/10