Lucy seems to like the word 'apple'.
Every time I give her food, I pronounce its name carefully. She hasn't picked up 'corn' or 'pepper' or 'bean'. Just 'apple'.
When she goes on one of her vocalizing streaks where she experiments with her voice with all kinds of sounds, from high-pitched chirps and screams to belly-growls, she always plays for a while with 'apple'. She prolongs the syllables and plays with the p's in her throat. It's interesting and odd, evocative of Eve and learning to read.