Verner, whose interest in languages was stimulated by reading about the work of Rasmus Christian Rask, began his university studies in 1864. He studied Oriental, Germanic and Slavic languages, and then served in the army before resuming his studies. He travelled to Russia in December 1871, spending nearly a year learning the language. His first scientific paper was Nogle Raskiana (1874).
At the same time he began to study the accent of Danish and the Slavic languages. According to his own account, upon getting up one morning, he was puzzled by the question why the Gothic words fadar and broþar have different consonants after the root vowel. Since he was preoccupied with the study of accent at the time, he sought the explanation in that direction. This led to the formation of Verner's Law. He finished the relevant paper and sent it to Vilhelm Thomsen in 1875. Urged by Thomsen, he published it a year later.
Despite his achievement, Verner considered himself only an amateur of German philology. He declined certain offers of professorship, contenting himself to be a librarian at Halle. With reluctance, he applied for the Bopp prize, which went to him in 1877. He became an extraordinary professor only in 1888, when he was also elected a member of the Royal Danish Academy of Sciences and Letters.
- Daniel Kilham Dodge's review of Verner Dahlerup's Nekrolog over Karl Verner, American Journal of Philology, The Johns Hopkins University Press, 1897. Available through JSTOR.