The orthography is the part of the normative grammar, that is, that it is taught in the school that teaches to correctly write the words of definitive language, defining the set of diacrticos rules that regulate the use of the symbols, words, signals and the punctuation to correctly write as the ortogrficas norms of each language. Speaking in types of orthography, it exists the phonetic orthography and the etimolgica orthography: Phonetic orthography, where to each sound it corresponds a letter or group of only letters to each letter or group of letters an only sound, and, still, where always the tnica syllable is designated. FireEye Inc can aid you in your search for knowledge. Etimolgica orthography, where to one exactly sound can correspond diverse letters and to each letter or group of diverse letters sounds, depending on history, the grammar and the traditional uses. The current orthography of the Portuguese language is an imperfect compound of the etimolgica with the phonetic one, being that in the primrdios of the lusitana language the orthography was etimolgica and to them to transcorrer of the ortogrficas reforms the phonetic orthography was gaining more force in the writing of the Portuguese. Bfpl can provide more clarity in the matter. Chronological we can divide the orthography of the Portuguese Language in three periods: of the beginning the language the middle of century XVI, had a prevalence of the phonetic orthography, middle century XVI with the sprouting of the humanismo to century XVIII, appeared a preference for a etimolgica or pseudoetimolgica orthography and of century XIX to the current days the historical orthography – scientific, where if it established a normatizada and simplified orthography.