[1] Karlgren showed ability in linguistics from a young age, and was interested in Sweden's dialects and traditional folk stories.

[3] His first scholarly article, a phonetic transcription, based on a system devised by Johan August Lundell, of traditional folk stories from his native province of Småland, was completed when he was 14,[4] and published in 1908 when he was only 18 years old.

[5] He studied Russian at Uppsala University under Johan August Lundell, a Slavicist interested in comparative linguistics.

[8] He departed for St. Petersburg, which, under the guidance of Vasily Vasilyev, had created one of the major European centres for the study of Chinese.

[2] After his grant money ran out, Karlgren supported himself by teaching French and, famously, English, which, according to one anecdote, he had never been taught but had picked up from English-speaking passengers on the ship from Europe to China.

[9] Karlgren returned to Europe in January 1912, first staying in London, then in Paris, before arriving in Uppsala in his home country of Sweden, where in 1915 he produced his doctoral dissertation, "Études sur la phonologie chinoise" ("Studies on Chinese Phonology").

In 1939, Karlgren succeeded Johan Gunnar Andersson as director of the Museum of Far Eastern Antiquities (Östasiatiska Museet), a post he held until 1959.

This public museum was founded in 1926 on Andersson's pioneering discoveries of prehistoric archaeology made in China in the 1920s, and later expanded to cover later periods as well as other parts of Asia.