Hmmm it really depends, I've worked with children at that age and while some of them just said a few words, others could keep talking for minutes if you let them to xD
I remember specially one activity I did with them, in which they had to create a story of their own and tell it to the rest of the classmates. Some stories were just like "Today I go to the park to play with my friends Andy and Anna", but other were something like "There were two sisters living in a forest and one day they went out and a monster appeared, then the monster started chasing them but..." and talked during a pretty long time ^^
But yeah, maybe the vocabulary shouldn't be so accurate, but it's for making the lecture easier :)
Hmmm it really depends, I've worked with children at that age and while some of them just said a few
