Languages rarely die because their speakers are forced to abandon them. More often they fade through a series of reasonable individual choices. Parents who want their children to succeed in school or find work speak the dominant language at home, and within a generation or two the older tongue survives only in songs, prayers and the memories of the very old. Linguists who study this process stress that the loss is not merely of words. Each language encodes a distinctive way of dividing up experience, from the names of plants to the ways relationships are described, and when it disappears, the knowledge stored in it usually disappears too.
Efforts to reverse the decline have had uneven results. Programmes that simply teach the language in classrooms often produce learners who can recite but not converse. The more successful revivals, such as those of Welsh and Maori, have depended on making the language useful in daily life: in broadcasting, in public administration and, above all, in homes. The lesson seems to be that a language is kept alive not by being preserved but by being needed.