Spanish (español) is used as an official language by the European Union and Mercosur and one of the six official languages of the United Nations. Spanish is a Romance language that originated in Castile, a region in Spain. Approximately 406 million people speak Spanish as a native language, making it the second-most-spoken language by number of native speakers after Mandarin. Spanish is a part of the Ibero-Romance group of languages that evolved from several dialects of common Latin in Iberia after the collapse of the Western Roman Empire in the fifth century. Spanish is a relatively inflected language, with a two-gender noun system and about fifty conjugated forms per verb, but with inflection of nouns, adjectives, and determiners limited to number and gender. Spanish is written in the Latin script, with the addition of the character. The Spanish alphabet has the following 27 letters and 2 digraphs.