I would like this thread to become a list of all the books you know that popularize linguistics (any field thereof) or that - more generally - are about languages and anything related to the subject. You can list books written in any language.
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Books in English (or translated to English)
-Languages of the World: An Introduction - Asya Pereltsvaig (about world languages)
-Don't Think of an Elephant: Know your Values and Frame the Debate - George Lakoff (cognitive linguistics)
-The Art of Language Invention - David Peterson (conlanging)
-La ricerca della lingua perfetta nella cultura europea (The Search for the Perfect Language in the European Culture) - Umberto Eco
Books in Italian (not sure if they've been translated to English)
-Dire quasi la stessa cosa - Umberto Eco (about translation theory)
-Storia Linguistica dell'Italia Unita - Tullio de Mauro (about the linguistic history of Italy after the Unification)
-La lingua geniale. 9 ragioni per amare il greco - Eva Cantarella (about Ancient Greek)