UN Declaration of Human Rights
It is a fundamental human right to receive schooling in your mother tongue(s). There is not a single human being on this planet who is born literate. We all have to be TAUGHT to read and write in our mother tongues. Yet this fundamental right is still denied to most speakers of minority languages in the world.
Shetlanders receive a minimum of nine years of rigorous schooling in English. For the last 200 years at least Shetlanders have been told that English is the "proper" language, while Shaetlan is not. This has no linguistic justification whatever. Shaetlan is as structured, solid and viable as any other language in the world. In a bilingual community like Shetland there is no linguistic reason why it cannot be used in teaching alongside English from P1 to S6 in any and every subject, including the sciences.