In the Mon-Khmer language Katu (as spoken in the Lao P.D.R.; Costello 1998), nominalization is marked with a variety of forms at the leftmost periphery of the root word, and occasionally as a phonologically reduced infix, /-r-/, appearing in the coda of the initial syllable of the nominalized word. This paper will analyze the Katu case as an example of prosodically conditioned allomorphy, resul...