Question

Why should one not forget its mother tongue? And does it really matter if old languages become extinct?

Answer 1

It is not so easy to forget your mother tongue…

If you only speak one language, your brain functions very differently than if you speak two or more languages.

Answer 2

Answer:

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The loss of language undermines a people's sense of identity and belonging, which uproots the entire community in the end. Yes, they may become incorporated into the dominant language and culture that has subsumed them, but they have lost their heritage along.