Grimm's law was the first discovered systematic sound change, creating historical phonology as a historical linguistics discipline. Friedrich von Schlegel first noted the correspondence between Latin p and Germanic f in 1806. In 1818, Rasmus Rask extended the correspondences to other Indo-European languages, such as Sanskrit and Greek, and to the full range of consonants involved. In 1822, Jacob Grimm put forth the rule in his book Deutsche Grammatik and extended it to include standard German. He noticed that many words had consonants different from what his law predicted. These exceptions defied linguists for several decades, until Danish linguist Karl Verner explained them in Verner's law.
Grimm's law was the first discovered systematic sound change, creating historical phonology as a historical linguistics discipline. Friedrich von Schlegel first noted the correspondence between Latin p and Germanic f in 1806. In 1818, Rasmus Rask extended the correspondences to other Indo-European languages, such as Sanskrit and Greek, and to the full range of consonants involved. In 1822, Jacob Grimm put forth the rule in his book Deutsche Gramm,atik and extended it to include standard German. He noticed that many words had consonants different from what his law predic:ted. These exceptions defied linguists for several decades, until Danish linguist Karl Verner explained them in Verner's law.