Children learn their mother tongue in the interactions they have with their caregivers. Yet, language is not only based on daily-life activities and Shared Book Reading (SBR) activities provide children with more different syntactic structures than spontaneous child directed speech. It has been demonstrated that SBR activities have a positive effect for children on a range of skills like vocabulary development (Payne et al. 1994 ; Snow & Goldfield, 1983), literacy (Bus et al. 1995), narrative development (Lever & Sénéchal, 2011) and grammatical development (Noble, Cameron-Faulkner & Lieven, 2013). Noble et al. (2013) showed that there is a relationship between SBR and grammatical development because written language contains a wider range and more complex set of sentence types than in child directed speech. Snow et al (1976) and Hoff-Ginsberg (1991) have also shown that language used during SBR involves higher mean length of utterance (MLU) than in spontaneous adult-child dyadic interactions. In line with those findings, it has been demonstrated that books can be viewed as a form of enriched linguistic input (noble et al. 2013). Thus, it appears that SBR activities offer a favourable context for children to acquire language because in comparison to spontaneous Child Directed Speech there are noticeable qualitative differences in the grammatical and syntactical structures used by the parents when addressing their children and by the children when commenting on the stories. The activity itself triggers a constant back-and-forth movement between the children's daily lives and the work of fiction they are reading and also prompts displaced speech on the part of both the parents and the children. It adds a new dimension to language itself since language is no longer used to do actions but rather to talk about displaced events or imaginary characters. For all these reasons, the present paper investigates the qualitative differences at work between spontaneous adult-child interactions and SBR activities. To do so we analysed the use of negation in SBR. Negation is a relevant topic because the parents and their children frequently use it. It may be expressed by the means of grammatical markers like the adverbs not or never, but it can also be expressed non-verbally by the means of gestures or actions. This study analyses the expression of negation in spontaneous adult-child interactions and in SBR contexts in two longitudinal corpora of one monolingual English-speaking child and one monolingual French-speaking child filmed one hour a month from one to four years old. Results show that in SBR activities the parents use a wider range of negative functions compared to daily-life adult-child dyadic interactions. The children also express generally low frequency negative functions like epistemic negation, denial and negative assertion in a larger proportion than in the rest of the corpus. Likewise, we observed that refusal - the most represented negative function in the corpus - is not predominant in SBR activities. The analysis of the expression and the use of negation in SBR is an ideal locus to look at substantial numbers of low frequency negative functions as well as to convey qualitative multimodal analyses on two different contexts of interaction: SBR and spontaneous adult-child dyadic interactions. References: Bus, A., van Ijzendoorn, M., & Pellegrini, A. (1995). Joint book reading makes for success in learning to read: A meta-analysis on intergenerational transmission of literacy. Review of Educational Research, 65, 1-21. Hoff-Ginsberg, E. (1991). Mother-Child Conversations in Different Social Classes and Communicative Settings. Child Development, 62, 782-796. Lever, R., & Sénéchal, M. (2011). Discussing stories: How a dialogic reading intervention improves kindergarteners' oral narrative construction. Journal of Experimental Child Psychology, 108, 1-24. Noble, C., Cameron-Faulkner, T. & Lieven, E. (2013). What's in a book? Communication in the Child Language Seminar, University of Manchester, June 24th, 2013. Payne, A.C., Whitehurst, G. J. & Angell, A. L. (1994). The role of home literacy environment in the development of language ability in preschool children from low-income families. Early Childhood Research Quarterly, Volume 9, Issues 3-4, 1994, 427-440. Snow, C.E., & Goldfield, B. (1983). Turn the page please: Situation specific language learning. Journal of Child Language, 10, 551-570. Snow, C.E., Arlman-Rupp, A., Hassing, Y., Jobse, J., Joosten, J., & Vorster, J. (1976). Mothers' speech in three social classes. Journal of Psycholinguistic Research, 31, 424-444.