The structure 'You [main verb] [object], you [auxiliary/modal]: 'You know everyt...

THE SARCASTIC BYSTANDER [not attending to her]: Do you know where I come from?
THE NOTE TAKER [promptly]: Hoxton.
THE SARCASTIC ONE [amazed]: Well, who said I didn’t? Bly me! You know everything, you do.
THE FLOWER GIRL [still nursing her sense of injury]: Ain't no call to meddle with me, he ain't.

Pygmalion By George Bernard Shaw

A few lines below we find a similar (emphatic?) structure:

'He’s no gentleman, he ain’t, to interfere with a poor girl.'

I wonder what style, register, etc. the repetitive structures like 'You know everything, you do' convey, and if they are common and idiomatic in everyday speech, and if you used them yourself. That is, would these be idiomatic:

1. John can run very fast, he can.
2. She wasn't born, she wasn't, with any health problems.
3. We will go there tomorrow, we will, unless it rains.

Here is what ChatGPT said:

It is a well-known feature of English called right dislocation or, more specifically in many British dialects, pronoun/tag repetition. It is especially associated with colloquial, non-standard, and dialectal speech, and in Pygmalion Shaw uses it deliberately to represent the speech of working-class Londoners. The repeated auxiliary or verb is not grammatically necessary. Its function is primarily pragmatic: it reinforces, emphasizes, or underlines the preceding statement.

Depending on context and intonation, it can express emphasis
insistence
emotional involvement
annoyance
sarcasm
certainty
It often sounds more personal and conversational than simply adding really or indeed. This construction is very common in many varieties of spoken British English (especially regional dialects), less common in standard written English.

In this case I would agree with Chat GPT's analysis. I don't think I use that construction myself, or very rarely, but it sounds perfectly natural.

However, it's normally only used to reinforce simple statements ("You're crazy, you are!") so your example 2 isn't idiomatic. In any case, the 'she wasn't' would have to go at the end of the sentence, otherwise it would suggest that she wasn't born at all. How about "She was born healthy, she was."?

I think your third example feels odd to me because you have used the formal 'we will go' with what is mainly a colloquial usage. "We'll go tomorrow, we will - unless it rains."