When you speak, let's say Spanish, while in the company of, let's say, English speakers, typically, it would be taken as rude because they don't know what you are saying. But this unspoken rule would have never been adopted if no one had ever experienced this situation. If asked, "Why would people do even do this?" my first consideration would be that it must be for some sort of personal edification. For example, a Spanish couple find themselves, alone, in a community of English speakers and so exercise their familiarity with one another in order to foster comfort and support from one another, at the risk of the others suspecting they are the subject of the unknown exchange. Consigned to existence in two worlds, I often find myself at a loss as to how to operate within them, if it were not for Holy Spirit guidance.
There were a couple instances that I've found myself aware that I was in a state of alarm for what seemed to be no reason, once with my son in mind and the other where my niece and her husband came to mind, but it was never accompanied with the feeling that I was helpless and "could do nothing" even if I did feel that helpless and could do nothing, if that made sense.
But at these times, I'd fall on my knees and pray in tongues and while doing so, a visual synopsis of the situation would be revealed to me, the first involving a picture of rain and a semi-truck and the second involving my niece riding shotgun.
These are only a couple of examples along with a time when I didn't even know a person, only the location, which was near enough associated to a personal loved one it would generate me to alarm, accompanied by a vision of a man, a vehicle, and a firearm.
But now, I don't wait for those types of alarms. I sort of just do 'walk-thru' safety checks.