Peter och Petra is a 1989 Swedish film directed by Agneta Elers-Jarlemann and based on the novel of the same name by Astrid Lindgren. Plot. Gunnar is in his classroom and has to read a text to whole class, something that Gunnar does not like at all. He does not read very well and the other kids laugh at him. Suddenly it knocks on the door and two tiny children are in front of the door. They introduce themselves as troll children and tell the teacher that they would like to attend classes. The teacher is surprised by the appearance of the children, but immediately agrees to teach the two.
https://en.wikipedia.org/wiki/Peter_och_Petra