It is not surprising that young children sometimes misunderstand expressions. There is a well-known children’s game called “Simon Says.” The parent or teacher gives the rule: Only do what Simon says. The adult then says, “Simon says touch your nose,” but sometimes says only “Shake your head.” Children are to comply with the first but not the second. Google provides a brief video as part of its entry for “Simon Says.” It reveals, what is often reported, three- or four-year-olds often comply with both, while slightly older children are more able to make the distinction, but all children love the game. The game is an early introduction to the rules for correct understanding. Understanding correctly is difficult because the main clause determines how the other clause is to be understood.