This article investigates the motivations for consonant cluster simplification through an analysis of consonant deletion in Icelandic, in clusters of three consonants created by the addition of the preterite suffix -ti/-di/-ði directly to the verb stem. It is argued that deletion is driven by perceptual factors interacting with sonority requirements. Deletion targets stops and nonstrident obstruents and its likelihood correlates with similarity in manner and place of articulation between the consonants and their adjacent segments. These two generalizations are elucidated in terms of perceptual cues, and an optimality-theoretic analysis is developed in which more perceptible consonants are protected from deletion by higher-ranked faithfulness constraints.I am grateful to Ólafur Páll Jónsson and Haraldur Bernharðsson, as well as Hanna Óladóttir, for patiently going through a long list of verbs with me and answering my questions. Haraldur also provided me with useful references and easy access to them. Thanks also to Michael Kenstowicz, Eiríkur Rögnvaldsson, and two anonymous JGL reviewers for answering questions, discussing different issues, and commenting on earlier versions of this research.

Martin Luther is universally acknowledged as an important figure in the history of German. Although the study of his language has been broadly covered in research, the study of his word formation is rather meager. This article gives an account of Luther's nominal word formation, excluding compounds. The material comprises three corpora: samples of his main works, extracts from the 1545 Bible, and a selection of his letters. The most frequent suffixes are: -er, infinitival -en, -ung, -ϕ, and -heit. The most frequent prefixes are un- and heubt-. The class-maintaining functions show the diminutive as the most frequent overall, whereas it is the abstract that is the most frequent among the class-changing functions. A comparison of Luther's usage with that of his contemporary Dürer shows agreement in the most frequent suffixes as well as in the most frequent function of both the class-maintaining and class-changing functions. Modern (New High) German shows a similar agreement in most frequent suffixes and functions although there are new prefixes and suffixes. Word formation changes, albeit slowly. Luther's word formation fits into his linguistic context and shows the same main features as Modern German.