I spent most of 1991 and 1992 in France. For the first bit, I was a nanny. This is Florence. She was a handful. I was 18 and didn’t have the skills to take care of a precocious three-year-old in my own language, let alone another language.
One day, Florence and I were disagreeing. She got so mad at me that she grabbed a stool from the kitchen, stood up on it, looked me straight in the eye, and said (very determinedly): “Tu est une salope, tu sais?” That stopped me in my tracks because I didn’t know what the word “salope” meant. She wouldn’t tell me.
It turned out she had quite a good vocabulary for a three-year-old. You can look up what she called me on Babelfish.