Hasse's pre-war letters are all in very fluent English, with some personal and general as well as mathematical news. His letters in German use the 'du' form right to the end.
G.116: 1932, Nov., Dec.
G.117: 1933, Jan.-June. Letter of 20 January has a ms. note by G.H. Hardy.
G.118: 1933, July-Dec. Hasse's letters of 20 and 24 October and 11 November include news of German mathematicians in Germany and abroad.
G.119: 1934. Includes material re Hasse's and Davenport's joint paper (Bibliog. 8), and Hasse's appointment at Göttingen.
G.121: 1936, 1938, 1939
G.122: 1946, 1947, 1949, 1952, 1963, 1967. (1967 death of Hasse's wife).