If I talk like people in Pride and Prejudice, will people laugh at me?

People may not laugh at you to your fact for attempting to affect archaic English phrasings and vocabulary in general conversation, but they will probably at least look at you oddly. It’s also doubtful that they would understand you, and isn’t that the point of communication? (Worse than “laughing at you” to your face, they may laugh at you behind your back.) However, it’s doubtful that you could pull it off effectively, and then you would feel foolish even to yourself.

Even native English speakers – even in the UK – would have trouble pulling this off in a way that wouldn’t look silly. If you’re just learning the language, then it would be better to learn it well in its modern usage before you attempt historical recreations.

If you want to attempt this, then I would suggest that you join a theater group that specializes in such period productions, where at least you would be among others who would be doing the same thing, and you can learn from them as you improve your own speech and coach others, too.

To answer your last question, I can generally understand the words, but the accents and some of the topical references sometimes throw me.

Why aye man, a mean howay, nowt cliva aboot tarkin arl posh like.

I’ve learned that people will laugh at you for damn near anything.
I wouldn’t worry to much about it. Haters gonna hate.

Speak Standard English, such as you hear on the BBC and you will be all right. I am fairly certain, however, that the English that Jane Austen spoke would be very different in pronunciation as well as in grammar and syntax from 21st century practice. Once, in a Linguistics class, I heard a sample of speech of Edward VII of Great Britain (1841–1910). It sounded like a foreign language.

@Katniss That.

I understand it. It’s not the greatest example of learning the language though. Try some of the cartoon movies. It may seem silly but they usually speak on a less intricate level that is easily understood. For example, when I went to Ecuador years ago I watched The Smurfs in French with Spanish subtitles. I didn’t know either language but I knew what was going on. It’s the best way to pick up a language I think.

That kind of accent is called “received pronunciation” and is still used among the upper classes and in southern England. It’s a good one for people who are learning English as a second language because it’s very easily understood. I don’t think that real people in the 18th century would have spoken that way though.