In Spain, people tend to say “ya” to mean “yes” or “I understand.” I don’t know if it’s a borrowed word or not.
Koreans use the word yeah a lot and it means exactly what it does in English. When listening to people speaking Korean I very often hear them saying ‘yeah, yeah’.
In fact, the Korean language has absorbed quite a few English words. As an example, the Korean word for computer, is computer.