Aomushi-wa, happa-o tabeta-kara aoku-natchatta-no? (Has the caterpillar turned green because it ate the leaf?)

Situation 1: Little Mariko is in the garden with her grandmother, looking at a green caterpillar on a leaf.

まり子:  青虫は、葉っぱを食べたから青くなっちゃったの?