The General Association of School Principals is calling for more mandatory language tests before school enrolment. "It must be ensured that children start school life with a sufficient vocabulary," said the association's chairwoman Gudrun Wolters-Vogeler.

She cited Hamburg as a role model, where children are subjected to a mandatory language examination long before they start school. In Germany, only a good third (34 percent) of the children surveyed answered "yes" to the question: Do you like to read?