The reasons are often political, economic, or cultural in nature. Speakers of a minority language may, for example, decide that it is better for their children’s future to teach them a language that is tied to economic success. For example, I know that in Haiti speaking Creole is discouraged in school and for the wealthier class, speaking Creole to adults is discouraged, at the very least from the hearsay that I picked up on my trip to the Dominican Republic. Languages also die when people of specific ethnic groups are all systematically killed. The death of culture and language are tied together. While a lot of languages spoken by Native populations may not be dead, the amount of people speaking those languages is significantly reduced due to the many genocides committed by U.S presidents. Linguists writing down languages and how they work, as well as keeping databases of the pronunciation of words is extremely important. The languages that are being written are all being preserved in an important way, and this for a matter of fact can bring a language back to life if enough of an investment is made in a population to continue speaking the language. They are being preserved with audio recordings, transcription into phonetic notation, and a variety of important initiatives carried out by activist groups that hope to defend their people from erasure.
Schools can promote students having an abundance of classes offered other than the European languages that we are forced to learn. Groups like the Endangered Language Alliance are also making a wave by stressing how fragile our languages and cultures are to erasure if they are not protected from the majority groups that do not acknowledge these languages.
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