On this last trip to Michigan, I got an amusing twist on being stuck in front of a screaming child. The family seated behind me was Francophone, so I got to practice my French while listening to the parents try (and fail) to get the situation under control.
It was a 4-hour flight, so I'll provide only a few snippets from my intensive language review:
"Descend! Tout de suite!" ("Get down! Right now!")
"On ne joue pas avec ça ; tu vas les casser." ("That's not to be played with; you're going to break it.")
"Ça, ce n'est pas gentil." ("That's not nice.")
and my hands-down, absolute favorite:
"Tu as besoin d'un (Do you need a) time-out?"