After her dismissal from the university, Sponer worked as a freelance translator while she was active in the resistance to Nazism, using her international contacts to help people escape from government persecution, which she was arrested for in 1942.

In 1919, Sponer finished her secondary education in Quedlinburg, after which she studied Romance and Germanic philology, in addition to Arabic at universities in several cities: Halle, Leipzig, Neapel, Grenoble, Madrid and Berlin.

[1] In April 1929, Sponer started working as an assistant teacher of Spanish at Friedrich Wilhelm University to support herself financially, prepare for exams, and complete her dissertation.

[1] During her time in Spain, she published several works on Romance languages in Iberia, including "Catalan dialects" (German: Katalanische Mundarten) distributed through the Institute of Phonetic Research on vinyl records in Berlin in 1931.

These were recordings of northern Catalan dialects accompanied by booklets with translations, phonetic transcriptions, and cursory notes on unique linguistic features in the introduction.

In her report of the trip she wrote of her economic incentives for going, alongside detailed information on the educational system of Mexico, and the statistics on foreigners in the country.

[1] Following her dismissal from the university, Sponer stayed in Berlin[3] and worked as a freelance translator, and was hired intermittently by the foreign ministry of Germany.