129 Family Matters: Lexical Aspects of Japanese Rendaku Jeroen van de Weijer Clemens Poppe Shanghai Int’l Studies University The University of Tokyo Marjoleine Sloos University of Groningen Abstract: Some roots in Japanese compounds always undergo the rule of rendaku, others never undergo the rule, and still others vacillate. In this paper, we investigate this kind of lexical variation from the perspective of the fre- quency of such roots. Different types of frequency are considered, such as that of roots in isolation, and the roots’ frequency of occurrence as a left- or right-hand member of compounds. We show that frequency is related to the likelihood of a root undergoing rendaku. Since rendaku also clearly involves phonological factors, we argue that this result should be interpreted in a mod- el which integrates usage-based factors with phonological grammar. 1. Introduction In this paper we discuss the Japanese rule of rendaku (lit. “sequential voicing”) from a combined generative and usage-based perspective. Rendaku voices the first segment of a compound if a number of conditions are satisfied. The his- tory of this rule, as well as its (ir)regularity and the conditions on its application in present-day Japanese, have attracted a great deal of attention in the morpho- logical and phonological literature. One aspect has been especially problematic for past analyses: even if all conditions on its application are taken into ac- count, rendaku appears to have a considerable number of lexical exceptions. That is, some lexical items are more prone to undergo the rule than others, on a seemingly idiosyncratic basis. In this paper, we show that the propensity of these roots for undergoing rendaku can be related to the frequency with which these roots occur in isolation as well as in compounds. Apart from contribut- ing to the solution of a long-standing puzzle in Japanese morphophonology, a general conclusion that can be drawn from this analysis is that the frequency with which words are used (both in compounds and in isolation), should be included in the explanation for their phonological behaviour. Since rendaku is also governed by purely phonological constraints (such as Lyman’s Law; see