I want to know whether it is permissible for the adhaan to be in a language other than Arabic? Is it permissible, for example, to translate the adhaan so that people will understand it?.
The majority of fuqaha’ are of the view that the adhaan is not valid in any language other than Arabic.
It says in al-Mawsoo‘ah al-Fiqhiyyah (11/170): Translating the adhaan: if the adhaan is given in Farsi or any language other than Arabic, then the correct view according to the Hanafis and Hanbalis is that it is not valid, even if it is known that this is a call to prayer. This is the apparent view of the Maalikis, because they stipulated concerning the adhaan that it must be in the prescribed wording. The Shaafa‘is discussed the matter further and said: If it is a call to prayer in congregation, and among them are those who know Arabic well, then it is not acceptable to give the adhaan in any other language, but it is acceptable if there is no one among them who knows Arabic well. But if a person is giving the adhaan for himself, if he knows Arabic well then it is not acceptable to give the adhaan in any other language, but if he does not know Arabic well, then it is acceptable. End quote.
See: Badaa’i‘ as-Sanaa’i‘, 1/113; ad-Durr al-Mukhtaar ma‘a Ibn ‘Aabideen, 1/485; al-Majmoo‘, 3/137; al-Insaaf, 1/413
With regard to translating it for the purpose of teaching its meaning in schools and the like, there is nothing wrong with that.
And Allah knows best.