Siwi is a Berber (also known as Amazigh; Afroasiatic) language spoken in the Siwa Oasis and the nearby, smaller oasis of El Gara. Together, they form Egypt's only Amazigh-speaking area. Drawing on oral texts and elicitation data collected since 2011, this grammar provides a comprehensive account of the language's phonology, morphosyntax, semantics and pragmatics, together with key typological features. Seventeen chapters are complemented by a glossary organized into four semantic fields and by four illustrative texts, consisting of two folktales, a historical narrative and a recipe, offering valuable insights into Siwi as it is used in everyday life.