Young children will often say ‘“tuck” when referring to the word ‘truck’. Is “tuck” a speech error or does it result from flawed articulation? They could also have stored the word ‘truck’ as ‘tuck’ in their mental dictionary, due to incomplete perception or storage of all the sounds. Learning to speak involves the simultaneous acquisition of knowledge at several different levels and practice with applying this knowledge swiftly and smoothly when required. Errors are bound to arise in the immature system, but they also highlight what needs to be updated to the learner. This learning process will be charted.

In everyday communication, the words we say matter, but also how we say them. The intonation in speech can create distinct differences in meaning (as in: “You’re leaving!” or: “You’re leaving?”) Intonation is a key characteristic of language, but how do listeners actually process it? The aim of this study is to investigate how people process intonation. A large group of listeners will take part in both new and existing tests of intonation, language, memory, and musicality. The results will show in what ways the skill of processing intonation is unique, and how strongly it relies on other skills.

Indo-European is the largest language family on earth, having as its members modern languages like English, Dutch, French and Russian, but also ancient ones like Greek, Latin and Sanskrit. All these languages ultimately descend from a single mother tongue called Proto-Indo-European. However, it remains unclear how Proto-Indo-European first split up into its daughter branches. The discussion revolves around the question of where in the family the Anatolian branch must be located. Currently, there are three opinions on this issue: (1) Anatolian is just one of the daughters of Proto-Indo-European. (2) Anatolian is the daughter that split off first. (3) Anatolian is in fact a sister of Proto-Indo-European. Of these three, especially the last possibility is very exciting: it implies that both Proto-Indo-European and Anatolian descend from an even earlier mother language, which has been tentatively called "Proto-Indo-Hittite". The present VIDI-project aims at definitively solving the debate on how the Proto-Indo-European mother tongue split up. The position of the Anatolian branch in the Indo-European family will be determined by using the cladistic method. A detailed comparison of the linguistic features of Anatolian with those of the other Indo-European branches, and a focus on where Anatolian deviates from the rest, will allow us to establish which of the three scenarios presented above is the correct one. The project is innovative since it will, for the first time, apply the cladistic method to the linguistic evidence not only from Hittite, the best-known Anatolian language, but also from the other, "minor" Anatolian languages. If scenario 3 proves to be correct, the project will provide a specification of the linguistic characteristics of the newly discovered "Proto-Indo-Hittite" mother language. Such a dis-covery would be of tremendous importance, adding hundreds, possibly even thousands of years to the prehistories of all Indo-European languages, including English and Dutch.

With a team of deaf and hearing researchers, Dr. Victoria Nyst, Leiden University Centre for Linguistics, will compare the gesturing of hearing speakers with the sign languages that emerged in villages with a high incidence of deafness in West Africa, to establish whether grammatical differences in sign languages can be traced to cross-cultural differences in gesture.

Research on infant cognitive development is often statistically insufficiently powerful and replicability is a serious problem. A consortium of four baby labs will replicate two fundamental studies, which play a key role in debates on the learning mechanisms involved in language acquisition (Marcus et al. 1999) and on the cognitive benefits of bilingualism (Kovács and Mehler, 2004). By replicating each study in all four laboratories, we can improve the statistical power of the studies and test the robustness of the original results from these two important infant studies.