During the feudal system in North Korea, there was a "Translator's Examination" similar to China's Imperial Examination every few years, starting with the Confucian classics in China and the culture and written language in China.
Because Korea was a vassal state of China in Ming and Qing Dynasties, it went to China to pay tribute every year. When something important happens, such as the weddings and funerals of Emperor China, Empress Dowager, Empress Dowager and Prince, they all rush to Beijing as soon as possible for "filial piety".
In addition, the accession to the throne of King Koryo and the award of the Prince are very important to the national rulers, and they should also come to Beijing immediately to report to Emperor China.
With such close diplomatic relations, North Korea relies heavily on translation. Therefore, the translation examination is as important to Koreans as the imperial examination is to the south of China, and it is a great event to promote and make a fortune.
Therefore, Chinese characters and Chinese were mastered by many people in ancient Korea.
As for the present situation, almost part of it is influenced by history, and the other part is Chinese characters learned from close trade relations with China.