Ferdinand de Saussure (1857-1913) is considered the father of modern linguistics. He taught a course in general linguistics from 1907-1911 that was published posthumously in 1916. In this work, he introduced key concepts in structuralism such as langue and parole, the linguistic sign comprising the signifier and signified, and the distinction between synchronic and diachronic analysis of language. Saussure viewed language as a system of signs defined by relationships between the concepts they represent and the sounds used to express them.