Languages of the Ottoman Empire
The language of the court and government of the Ottoman Empire was Ottoman Turkish, but many other languages were in contemporary use in parts of the empire. Although the minorities of the Ottoman Empire were free to use their language amongst themselves, if they needed to communicate with the government they had to use Ottoman Turkish.
Islam in the Ottoman Empire
Since the founding of the Ottoman Empire, the Ottomans followed the Maturidi creed (school of Islamic theology) and the Hanafi madhab (school of Islamic jurisprudence). However, it was the Ash'ari creed that was more prevalent in the madrassahs (Islamic schools). Both the Maturidi and Ash'ari schools of Islamic theology used Ilm al-Kalam (reason) to understand the Quran and the hadith (sayings and actions of Mohammed and the Rashidun) so as to apply Islamic principles to fatwas (Islamic rulings). This is in contrast to the Athari (or literal) school of Islamic theology which takes the Quran and the hadith literally.