The Sign Language Typology Series is dedicated to the comparative study of sign languages around the world. Individual or collective works that systematically explore typological variation across sign languages are the focus of this series, with particular emphasis on undocumented, underdescribed and endangered sign languages. The scope of the series primarily includes cross-linguistic studies of grammatical domains across a larger or smaller sample of sign languages, but also encompasses the study of individual sign languages from a typological perspective and comparison between signed and spoken languages in terms of language modality, as well as theoretical and methodological contributions to sign language typology. We started talking about sign languages and deaf communities, and, becoming more and more surprised at all the strange facts I was bringing to his notice, he summed up our discussion with the words: "I only came to find a new television, but I found a whole new world!". Since 1994, my work in the world of deaf communities in various countries has brought with it a constant stream of memorable moments. A nightly journey in 1998 on a bicycle-rickshaw through a quarter of the old city in Delhi to visit a deaf family, in almost total darkness due to one of the usual electricity cuts. The first Indian conference on bilingualism in deaf education in Hyderabad in 2001. A long evening in Eskişehir learning the local games of chance in the deaf club together with some of my first Turkish signs. A week trapped in snowstorms in the worst Istanbul winter in decades, and severe Monsoon floodings in Mumbai. And above all, the long nights of relentless and addictive signing.Working in developing countries means working under the constant strain of insufficient resources and, at times, personal hardship, but more often than not, this is counterbalanced by the amazing human resources to be found in the deaf communities themselves. I gratefully acknowledge that they have been my main source of inspiration, and so it is to them that I wish to dedicate this volume.On the academic side, I am no less grateful to the many people who have accompanied me on various stages of the journey towards the beginnings of sign language typology. I owe a lot to the Research Centre for Linguistic Typology (RCLT) in Australia, which was my host institution in Canberra and in Melbourne between 1999 and 2003. The framework for a large cross-linguistic study on negatives and interrogatives in sign languages, which has resulted in the present volume, first took shape at the RCLT. The subsequent development of the project is something that still surprises me. Having designed questionnaires and contacted possible collaborators around the world, the sensible expectation, which luckily I was not aware of at the time, would have been to get some basic information from a handful of respondents, if not less. Instead, I received responses for sign languages from 18 countries, varying from a few basic written answers to complete 20-page papers. Mo...