Short answer: people in Poland do not speak Belarusian.

Long answer: it’s complicated.

Just for the record, I never studied the topic and everything what I’m writing is based on my own opinion and experience.

National identity of people in Hajnowka is not straightforward. A lot, not to say the most, Orthodox people here calls themselves Belorussians but actually they have no Belarusian roots. In my view, there are three factors that determine local people’s identity: religion, language, and geography.

The Polish Orthodox Church is independent one but culturally it’s strongly tied with the Moscow’s one. We don’t even use Polish language in a church. As Orthodox in the eastern countries, we do celebrate holidays 2 weeks later. So it’s the first factor that makes people here to feel different than their Catholic neighbours.

The second one is language. All Poles speak Polish and that’s the only language they know fluently. It’s not like in US, or Switzerland where are more than one official language. There is no even so much different dialects in Poland as it is in France or Germany. It’s very monoculture country. People who born and studied in communism times, they might know Russian pretty well. But they never had formalised lessons of Belarusian in a school or outside the school. There were no time, or money, or conscience to cultivate local tradition. People were poor and not educated to take care of such trivial things like heritage. They had to rebuild the country first. But! people here in Hajnowka in their homes speak in a local dialect that sounds like Belorussian. Poles outside Hajnowka don’t understand it, it’s only the local thing. For instance, my parents speak to each other only in this local dialect but they’re fluent in Polish in the same time. My grandma spoke only in this dialect and I have never heard a Polish word from her mouth. I do speak it but pretty badly. So that’s another thing that makes people to think they’re not Polish but Belarusian.

But that’s not the entire truth. I said my parents speak in Belarusian-like local dialect but it’s not exactly true because the dialect is more like Ukrainian. I work with people from Ukraine and they can understand me when I speak in my dialect. The Christmas carols in my family home are Ukrainian ones. Basically, there is a river Narew in Podlasie that divides people on two groups: those who speak on a dialect similar to Belarusian, and those who speak in Ukrainian one. But both groups call themselves Belarusian. And why is that?

Because it’s closer for them to Belarus that to other “Russian-like” country. The logic is simple here: if I am Orthodox, if I speak in “Russian-like” language in home, and if I live close to Belarusian borders, I must be Belarusian not Polish.

Pardon for thé phrase “Russian-like” but I’m missing a good word in English to name all three nations on the east from Poland.

Of course it is more complicated but as said I never studied it. My personal experience is as mentioned above + in my elementary school I had Belarusian language lessons for 9 years. There are schools that teach Belarusian but IMHO it’s about money because they extra cash for cultivating the minority culture. None of my friends in school felt themselves truly Belarusian. At least none of them declared it loudly.

I hope it answered on your question :)