How did most English people talk during the early 1800's?

If you want to get some idea of the use of English in Regency England from fiction, Bernard Cornwell's Sharpe novels are well researched from the point of view of use of English as well as historical detail, and Alexander Kent's are even better in this respect.

Or, if you want to try the 'airport fiction' of Regency England (stagecoach fiction? packet ship fiction?) Jane Austen and Sir Walter Scott were the two great best sellers of the age. That way, you are reading the Regency English of Regency writers.

You might try some Press archives of the period, not only the Times but local papers, but remember that written and spoken English are not always the same thing. Cobbett's Political Register is quite fun, or, if you would like to read two opposing views, Thomas Paine's Rights of Man and Edmund Burke's Reflections on the Revolution in France.

Hope this helps!

Did you mean people from England or english-speaking people? Mark Twain was an American writer & Dickens was English, so I'm slightly confused here. I've listed some sites for 19th-Century American & English slang & idioms, but it's harder to find more comprehensive sites. I'm going to pass the buck on this one & suggest you consult a local librarian or english teacher; you can also use a search engine to look up "19th century slang" "19th century english language" etc. Good luck!

Then as now, there were regional accents and usages in England (and the rest of Britain), there would not be one accent that covered all England.

sign language?............no i think in gaellic?