Old fashioned 2nd s.p. : "Thou"

[Fabio]

While reading some books (e.g. The Scarlet Letter by Hawthorne), I ran across the old fashioned 2nd person singular "Thou".

I know that that pronoun is no longer used for centuries in common English.
Anyhow, is there any region all over the world using it nowadays?
Or is there any context where "Thou" can be used?

Moreover, what are the verb conjugations for the 2nd p.s. "Thou"?

[JJM Ballantyne]

Second person singular "Thou/thee/thy/thine" has more or less vanished from English as a whole.

You will still find it employed in theological language and liturgy, particularly by those Christian denominations who use the King James Bible. Also, some members of a few religious groups - the Society of Friends (Quakers) for example - still resort to it in day-to-day speech.

Lastly, a dwindling number of English dialects use some form of it (the Northern English "tha").

The second person singular conjugation is "-(e)st" for most verbs (e.g., "thou walkest" and "thou seest"). A few irregular verbs have particular forms:

be/art/wert (or wast) have/hast do/dost

And even modals had second person forms:

wouldst shouldst/shouldest wilt mayest canst couldst etc.

JJM

[dihen]

Did 'thou' and 'thee' use to be the informal 'you' in the past?

[Fabio]

Did 'thou' and 'thee' use to be the informal 'you' in the past?

As far as I know, the answer is : Yes, they did.
I found the "Thou" pronoun in a text reporting a familiar or friendly speech between novel's characters. The novel is set in the 17th century.

However, I'm not a native English speaker. Someone else will be able to confirm or not your supposition.

[Tdol]

Yes, they were the familiar pronoun forms. They were still widely used in some dialects until and in the twentieth century.