According to Dr.Cumberland, a dying

According to Dr.Cumberland, a dying languages needs a dictionary and people to understand and record its grammar. Most importantly, you need to listen to those who still speak the languages. This can be very difficult, especially if there are very few speakers of the languages left. For example, when researchers were working to save the languages Ayapaneco in Mexico,it was hard for them to record anything because the last two people on Earth who could speak the languages refused to speak to each other!