For example, I think Mandela said in one of his speeches that one of the firsts things that a white person could do towards overcoming previous separation would be to learn indigenous languages. (though he might have been wrong about many things this does strike me as an obviously desirable and genuine gesture towards undoing divides)
And then there's also the fact that it was part of the work that the Zapatista guerrilleros like Marcos did:
While Marcos had come [to Chiapas] to teach politics and history to the communities, he quickly discovered that this revolutionary education, steeped in its own assumptions, made no sense to the communities (ibid., p, 166). In effect, the urban guerrilleros had to be reeducated and become new subjects capable of inhabiting the realities of the indigenous southeast if they were to be anything other than another failed group of radicals preaching incomprehensibly and ineffectually in a vain effort to recruit followers to their cause. This reeducation process included: learning indigenous languages; slowly coming to comprehend radically different ways of making sense out of the world; renouncing a politics based on Euro-Enlightenment assumptions and subordinating their own political expectations to the needs of the communities themselves; and giving up on a revolutionary politics of the vanguard and embracing a collective decision-making process grounded in the collective. The nondogmatic, radically democratic, and self-reflexive approach to radical social struggle and transformation that would come to characterize the Zapatista movement is poetically encapsulated in another Zapatista slogan, preguntando caminamos, “asking, we walk.”
Of course, it may be that the language has been wholly destroyed, and in places where it has been mostly destroyed it would not have the same effect to learn the languages where they are quite common (as in Mandela's country). But if not language then, what else can be done?