同慶帝
When Kha returned to Vietnam in the late 1870s, he had originally planned to become a Catholic priest. However, the newly established French colonial state needed someone to help them with interpreting. Thus, together with Nguyễn Hữu Bài, Kha became an interpreter. Later, he joined the Nguyễn civil service. He managed to pass all the sessions of the Imperial Examinations owing to his firm grasp of the Chinese Classics. He then went on to serve as a military command advisor under Emperor Đồng Khánh. Following that, he left the service to take care of his mother.