> I think some of it might be the convenience of being able to speak to one another without the children knowing what is being said as well. My father's parents

> I think some of it might be the convenience of being able to speak to one another without the children knowing what is being said as well. My father's parents knew German and he wasn't taught, but recalled many times where his parents would speak German to each other in front of him, ostensibly so the children couldn't understand. It was the same with my parents but more out of necessity than a deliberate act. I grew up with 4 languages but my parents spoke another 2. It would be difficult to understand those extra 2 languages as they had different scripts and were really different in nature. The result was that my parents used it as an encryption framework to have a private conversation while I was around. I understood zilch.