Representation on the Diachronic Change of English kn-cluster in Optimality Theory

In Optimality Theory (OT: McCarthy and Prince 1993, Prince and Smolensky 1993/2004), sound change is accounted for by constraint reranking. However, it does not properly show the ``gradual`` aspect of a diachronic change, though the unranking process is introduced for variation e.g. [knou] > [knou, nou] > [nou] (Cho 1998). Following Oh (2002), this paper proposes an alternative approach to the representation of historical sound change within the OT framework, on the basis of the sound change of know ([knou] > [hnou] > [nou] > [nou]) in Early Modern English (Dobson 1968). To show the gradual changes of [k], MAX, *VL NAS, IDENT [cont], and *σ[kn- constraints are interacted with each other. To display the gradual change of frequency among variants, the meaning of dotted lines is reinterpreted as weak domination contrary to that of straight lines as strong domination, based on Oh (2002). This paper concludes that gradual diachronic changes can be fully represented within the framework of OT through a series of unranking, reranking and ranking tools.