aboriginalaustralians congresses disparition documentation endangeredlanguages germaniclanguages grammaire grammar historicallinguistics history langageetlangues language languageandlanguages languageattrition languagemaintenance languagerevival languages languesaustraliennes morphology murder ngumbinlanguages northamerica poetry sociolinguistics variation walbiri(langue) wales warlpiri(australianpeople) warlpirilanguage welshlanguage