Do you regularly use the word "ain't" in conversation?

I have used it but not very often.

No, practically never unless I were quoting someone. But, as pointed out in the article, it was common educated class usage in the 19th century.

Only when being ironic

Only when I mockingly imitate a person of diminished intellectual capacity.

Rarely.

Very rarely. Pretty much only in one joking way or another, or in a quote/reference of some line.

e.g. “Ain’t nobody got time for” [X].

It’s a perfectly valid word, but I don’t use it.

I uaed to often as it’s fairly common here in rural Missouri. But as @Zaku mentions it’s often jokingly and intentional as an adult.
When I am around people who are more rural and use the old speak, I can easily slip into that childhood vernacular and sound extremely country. So much so I don’t notice myself doing it but friends and family do.
I’ve been told I sound like I’m from the Deep South on occasion, but speaking to the coastal clients I mimic their speech.

I don’t.

Interestingly, I heard it used in a very powerful way last week. While I was on Civil Rights tour of the South, we saw some teenagers sitting on the steps of the 16th Street Baptist Church and singing, “Ain’t Gonna Let Nobody Turn Me Around.” That is the church in Birmingham that was bombed and in which the four young girls were killed in 1963.

I regularly use ain’t as a contraction for am not.

@beancrisp I suspect this might be a regional thing. Can you share what part of the country you’re from?

Sho nuf!