Like anywhere else in the world, people do speak "dirty" sometimes. We are creatures of habit, but the most important thing that comes to mind is knowing the time and place to speak dirty. Usually its spoken with close friends or even a significant other. But a "dirty language" that I'm not quite sure about. All languages have bad words, its just whether you use it.

There's a time & place for everything, but you can be sure our young friend Brandon won't agree.

在美国大多数人至少偶尔说脏话，甚至有些人经常说脏话。 I would say the vast majority of people at least occasionally use "dirty language", and quite a few use it often. I myself do. There's nothing really wrong with it.

people cannot speak dirty language in usa and uk