زبان و خط رسمی و مشترک مردم ایران فارسی است. اسناد و مکاتبات و متون رسمی و کتب درسی باید با این زبان و خط باشد ولی استفاده از زبانهای محلی و قومی در مطبوعات و رسانههای گروهی و تدریس ادبیات آنها در مدارس، در کنار زبان فارسی آزاد است.
The official language and script and the common language of the people of Iran is Persian. Official documents, correspondence and texts and textbooks must be in this language and script. But the use of regional and ethnic languages in the press and mass media, and the teaching of the literature of these languages in schools, as well as Persian, is permitted.
Theoretically this provides enough leeway for other languages to carve for themselves a space in the education system. However in practice, as far as I know, only one other language is used as a language of primary and secondary education, and this in a limited way.
This is Armenian within the context of Armenian national schools. It is a kind of parallel education system which goes from kindergarten to high school, where Armenian children study their own curriculum rather than the Islamic one. They have Armenian classes and classes on Christianity (the vast majority of Armenians are Christians), and these classes are given in Armenian. In fact, the special dispensation goes further because if an Armenian child goes to a mainstream school, they are exempted from religious studies, and they get Armenian language classes outside of this school.
Note also that the Constitution allows mass media and press to be in other Iranian languages. In practice, only the largest linguistic minorities accrue enough funding to fund their own news and cultural products (theatre, music etc) in their own languages, such as Arabic, Azeri, Balochi, Kurdish or Mazandarani. Most of the cultural products produced in Iran, on a national and provincial level, are funded by the state, and the state privileges products in the Persian language.
I want to understand why Iranian languages are not being taught in school. Why do Iranians not enjoy the right to have an education in their own mother tongue that their own Constitution recognises? Who are the major actors? Who are the activists who are fighting to save their languages? Who are the actors who work to thwart them and maintain Persian dominance in Iran?
To do this, I need to have a better knowledge of Iranian politics and society. But to have a better knowledge of Iranian politics and society, I need to know more Persian. It's as simple as that. My level of Persian is currently insufficient to understand Iran.
An intriguing bit of information is that the فرهنگستان زبان و ادب فارسی, the Academy of Persian Language and Literature, states that one of its objectives is:
بهره بردارى صحيح از زبانهاى محلى (در داخل و خارج از ايران) بهمنظور تقويت و تجهيز اين زبان و غنى ساختن وگستردن دامنۀ كاركرد آن؛
The correct utilisation of the regional languages (both within and outside of Iran), with the goal of strengthening and equipping the language and enriching it, and extending its domains of usage/its functional domain.
The Academy which was created in 1935 in conscious imitation of the monolingual language academies of Europe (such as the Académie française) at least on paper acknowledges that it has a responsibility towards other Iranian languages. Not to keep them on life support but to help them flourish and grow. Promising to extend the domains of usage of a minoritised language is serious business, because it directly threatens the hegemony of an H language in a diglossic situation.
But as the Spanish saying goes, del dicho al hecho, hay mucho trecho. Even if the Academy did take its mandate seriously, its range of action is limited. Top-down changes to language policy take place in the halls of political power.
A simplistic measure (but not for being simplistic, less correct) would be affirmative action with regards to the minoritised Iranian languages. Special funding should be given to other Iranian languages. There should be a mandatory quota on how much media space is given to other languages, especially in Tehran. In areas where say, 20% of the population speak another language, all students should have the option to study in their mother language, from primary to high school. Of course, this would fly in the face of the centralising tendencies of Iran for the last hundred years...