Are Koreans in China Koreans? How can you speak Korean?

Koreans in China are from China, to be exact, their ancestors are Koreans or Koreans. The reason why they came to China has been made clear upstairs. Of course, they came from China and took root in China. Now more Koreans are married to the Han nationality. As for language, Koreans use Korean. Nowadays, young people use Chinese more, but when they first go to school, they have to go to a Korean school and use Korean as their mother tongue. It is not exactly the same as Korean, such as foreign words in Korean. There are also differences in pronunciation.