As a kid I would sing it happily because it sounded like such a happy song. Then in French class we learned what it actually meant.
“Alouette, gentille alouette. Alouette, je te plumerai.” This means, “Lark, nice lark. Lark, I will pluck you.” The song goes on to name all the different body parts that will be plucked of feathers, including the head, beak, throat, back, wings, feet, tail, and, in some versions, the eyes. Creepy, much?
My favourite term of endearment in French is “mon chou” which translates literally as “my cabbage” but is very sweet when used between a couple. I think it would be the English equivalent of honey, or dear.
Once at my piano recital, before the performances started, a woman was speaking French to her daughter and, naturally, I listened in. She told her to go up, play her piece, then bow and go back to her seat. Then she said, “Bonne chance, mon petit chou!” Even with my then-limited understanding of French, I was ecstatic to hear the term used in real life. So cute. :D