Constructor.

first of all I will try to simplify it,with using somethings that childrens like.

I will choose the example of choclat,and I will buy for him some choclat and tell him about the source of it,he will answer ,from seller
sellerˈseller,then Iwill add other question and the seller briguet it from where he will answer by I don’t know,then I will add by saying that