Wichita
Wichita is a Caddoan language spoken near Anadarko, Oklahoma, USA. There are 2100 enrolled tribal members but only about 10 elderly people actually speak the language.
The language is structurally prototypical of polysynthetic languages; i.e. most of the information in an utterance is contained in bound verbal morphology. There are no overt subclasses of nouns, and nouns occur either alone, incorporated, or in a locative or instrumental case form. There are no prepositions or postpositions, and the relevance of the concepts of "phrase structure" and even "sentence" (as opposed to "word") to the grammar is debatable. Verbs consist of from four to more than a dozen morphemes from about 35 rigidly ordered position classes, and are typically five to ten syllables long. The phonological inventory is extremely small -- 10 consonants and 3 vowels, two length contrasts and one pitch contrast -- but the morphophonemic rules for assembling words are quite complex.