khmer or Youn restaurant ?

I visited Cambodia for a coupe of weeks, I went to the Restaurant, some small Restaurants.
I command the food, and some drink. I saw some people who work in that restaurant.
I talked to them, asked them for Som Lor MaJu Krerng. they said, yes. then i waited for a few minutes, they didn't finished yet. then I walked to the bathroom, I heard them talking, I tried to listen to them, wow they could talk Youn!!!!!!!!!!
then i came back, enjoyed my food. After I finished I looked for the motor driver back home, he said, most of Restaurant in Phnom penh belong to Youn!!!!!!!!
Most of Youn, they speak khmer very well, like the PP people do, Oh my country !!!!!!!!! most of them have Khmer identification cards. but some of khmer no identification cards.