Brahmi is an abugida which uses a system of diacritical marks to associate vowels with consonant symbols. The writing system only went through relatively minor evolutionary changes from the Mauryan period (3rd century BCE) down to the early Gupta period (4th century CE), and it is thought that as late as the 4th century CE, a literate person could still read and understand Mauryan inscriptions.[9] Sometime thereafter, the capability to read the original Brahmi script was lost.