This book studies the linguistic phenomenon of Raddoppiamento sintattico (RS), the post-lexical lengthening in Italian of word-initial consonants following certain words, e.g. a [k:]asa ‘at home’. Linguists have long sought describe exactly where and why RS occurs. Based on naturally occurring speech recorded in Siena, Tuscany, this book provides detailed phonetic information on what happens when RS occurs as well as its interactions with other phenomena in natural speech such as lenition and pausing. This study relates this phonetic detail to existing phonological models of RS, vowel length and syllable structure in Italian. The most important subject of the book is the fine-grained description of stops in RS contexts, which are shown to be optionally preaspirated - a phenomenon typically associated with only a few languages outside of Scandinavia. The book considers in detail the potential role of preaspiration in signaling consonant length in this variety of Italian and in doing so serves as a useful model for other laboratory phonology investigations into connected speech processes.