Melanchthon himself had meant his book to be used by a teacher who was supposed to explain things more clearly to his pupils. He often gave directions to the teachers, saying, for instance, ‘I leave this for the careful teacher to explain to his pupils’. In reality, teachers often felt insecure, and followed the text slavishly. The insistence on uniformity did not encourage improvised explanations. Jersin described his own experience of learning Latin as a boy. He found it particularly difficult to get to grips with the Melanchthonian rule Substantivum cum substantivo genitivo casu iungitur. ‘One noun is joined to the other in the genitive case.’ This is all Melanchthon says about the use of the genitive case, and the young Jersin was beaten for six years, in three different schools, because he did not understand which of the two nouns should be put in the genitive. Nobody told him, until he moved school again and a teacher had the sense to explain it to him in Danish. Melanchthon’s grammar required intelligent teachers, the one thing central government cannot create by decree.