This book looks at the interaction between pragmatics, prosody, and lexical contrast as factors that condition variation in pitch and duration in two closely related dialects of Croatian and Serbian. The dialects differ in the presence or absence of a lexical contrast for phonological pitch and for vowel duration. The research is based on an acoustic study of pitch and duration, and the results indicate that cross-dialectal variation in prosodic features can be as large as the variation that is found across distinct languages. An important finding is that the expression of narrow focus is limited by the existence of lexical prosodic contrasts. This study sheds light on the principles that govern the phonetic implementation of lexical, prosodic, and pragmatic information, and has implications for intonational phonology and the typology of prosodic systems. This study also makes a significant contribution to Croatian and Serbian dialectology.