In this century, more people are speaking English than ever before. While this is convenient for English-speaking people, it has a down side: other languages, and the ideas that have been preserved in them, are becoming endangered.
Michele Starkey reports on recent efforts to preserve the Salish language that used to be the predominant language in the Pacific Northwest:
Here's a web page that attempts to link and organize what's available to the public about all the Native American languages:
(This link will help readers make sense of some, not all, of the nicknames this blog uses to conceal the identities of real people: http://www.native-languages.org/cherokee_animals.htm.)
The other language that might have been spoken by the ancestors of some people in my part of the world is Yuchi. Over at the Yuchi web page, Woktela reports that this language has to be spoken differently depending on whether you're male or female and on whether you're a Yuchi or a non-Yuchi; enough things are said differently that he feels that it's almost a set of different languages...
If you're researching a particular language, more information may be available at a particular nation's or group's web page, but it's generally advisable to consult someone who actually speaks the language for help. Even with the languages that are easiest for English-speaking people to decode, like Spanish or Italian, you need to hear a language spoken in order to speak it.
Not only are these languages harder for English-speaking people to learn than any European language is, having completely different grammar and phonetic systems, but some people actually don't want foreigners presuming to study (or "steal") their languages. Here's a link to a science fiction story that explains this phenomenon without referring to any real individual: