Abstract Phonetics describes the sounds of language. Learning how the sounds of English are pronounced puts us in a better position to understand some of the allomorph we encounter in English words. The same principles also bring out striking similarities between Latin, French, and English words despite several hundreds of years of sound changes. An example is Latin *cape, the source of the French word chef and, through French, the source of the English words chief and chef. Basic phonetics also helps us to appreciate the similarities among the Germanic languages and Latin and Greek, despite several millennia of sound changes. For example, in chapter 10 we trace the English word fire back to the same source as the Greek root pyr, showing along the way that the difference in pronunciation between /f/ and /p/ is a highly regular one.