Quechua is now written in the Latin alphabet despite the fact that its phonological system is very different from Indo-European languages. The transcription system therefore requires considerable work. Starting in 1580, a graphic system was put into place for speakers of the language, a system that remained valid until the middle of the 18th century. Other systems were later elaborated but were not very consistent. It was not until the middle of the 20th century that a genuine unification and simplification of systems was created. This phonologically based system is still currently used in Peru and Bolivia.