I recently read a very refreshing article on Moving Smart titled; MY LITTLE HERO: How Kids Learn Responsibility, that discusses this type of play. The writer goes on further to illustrate that even though boys and girls choose different toys while engaging in this play, essentially, the meaning behind their dialogue and choice of toy with it is the same. Take a look for yourself...
Interesting view isn't it?
The famous psychologist Lev Vygotsky studied thought and language development in young children, which contributed to findings that children do not develop an inner voice until around age seven. This gives adults an opportunity to "listen in" and help a child sort out what they are trying to understand a loud. I've been able to talk to my son about behaviors of other children he doesn't understand, and why he had to have all those shots that he disliked so much. They were views inside his head that I may not have had otherwise.
Take advantage of this window to help scaffold your child's understanding of what perplexes them. If anything, "listen in" to keep those embarrassing comments to a minimum that seem to pop up now and then when out in public!