English summary: At one time, people thought that the Greek word crocodeilos was derived from krokos (saffran) and deilos (fearful), which made the crocodile an animal who was afraid of saffran. As a result of erroneous knowledge, people were retaining three words instantly and everyone, like young Montaigne, was reading Latin fluently. Today, linguistic sciences have made prodigious strides, but readers of such languages have become very scarce. To fill in the gap between increasingly scholarly specialists and increasingly powerless amateurs, the author chose to be the first to relate in a broad outline the history of linguistics and, in the process, the key stages of this other amazing collective adventure that was the constitution and evolution of an illustrious language of civilisation. First there was the Indo-European legacy, foreseen as early as the 18th century, which discovered Sanskrit and invented a new account of its origins; then came enrichment: work done by the language on itself by prefixation, suffixation and composition; polysemy, which falls under semantics and endows each word with a multiplicity of meanings; and lastly evolution, which led to the Romance languages, and particularly to French, in which Latin is still transparent enough to be read. Thus there are not one, but several, small vocabulary lessons, progressively presented and illustrated by abundant lists that readers can occasionally dip into and learn from, or enjoy - a thousand everyday words so well explained and so evident that recalling them becomes automatic and effortless. French description: Il fut un temps ou l'on pensait que le mot grec crocodeilos venait de crocos (safran), et de deilos (peureux), ce qui faisait du crocodile l'animal qui a peur du safran: grace a un savoir errone, on retenait trois mots d'un coup et chacun, comme le jeune Montaigne, lisait couramment le latin. Aujourd'hui, les sciences du langage ont fait des progres vertigineux, mais les lecteurs sont devenus fort rares.Pour combler ce fosse entre les specialistes, de plus en plus savants et les sympathisants, de plus en plus desarmes, on a voulu, ce qu'on n'avait pas encore fait, retracer a grands traits l'histoire de la linguistique et, a travers elle, les principales etapes de cette autre formidable aventure collective qu'aete la constitution et le devenir d'une grande langue de civilisation.D'abord l'heritage indo-europeen, pressenti des le xviiie siecle qui decouvre le sanscrit et invente un nouveau recit des origines; puis l'enrichissement: le travail de la langue sur elle-meme par prefixation, suffixation et composition; mais aussi la polysemie, qui releve de la semantique et distingue dans le mot une multiplicite de sens; enfin l'evolution qui conduit aux langues romanes et en particulier au francais, ou le latin se lit encore par transparence.Ce sont ainsi non point une, mais plusieurs petites lecons de vocabulaire en gradation, illustrees par d'abondantes listes, ou l'on pourra piocher et a l'occasion s'instruire ou se divertir: mille termes usuels, tellement justifies, tellement evidents qu'on les retiendra comme par surcroit et sans peine.