Upon returning to United States, he completed the remaining requirements for his MA, which was awarded in 1935. As he had already received a DLitt from the University of Rome, he chose not to pursue a PhD at Chicago.[1]
In 1943, he went to work at U.S. Armed Forces Institute (USAFI) in Washington, where he helped to produce textbooks for French, Italian, Spanish, and Portuguese as part of the "Spoken Language" series. This series was to have a significant effect on the teaching of foreign languages in the United States. He also contributed to the Armed Services Training Program (ASTP).[1]
At the invitation of J Milton Cowan, Hall joined the faculty at Cornell in 1946 and helped to found the Division of Modern Languages there. When he retired in 1975, he received the title of Professor Emeritus of Linguistics and Italian.[1]
In addition to the Romance languages, he had a strong interest in pidgin and creole languages.[1] He also took an interest in the controversial Kensington Runestone, which he believed to be genuine.[3]
In 1936, Hall married Frances L. Adkins, with whom he had three children (one son and two daughters).[1][4] After Adkins's death in 1975, Hall married Alice M. Colby-Hall.[1]
A fan of P. G. Wodehouse, Hall wrote a book on Wodehouse's comic style and served as the president of the Wodehouse Society from 1983 to 1985.[1]