The languages of Bolivia include Spanish; several dozen indigenous languages, most prominently Aymara, Quechua, Chiquitano and Tupi Guaraní; Bolivian Sign Language (closely related to American Sign Language); and language of immigrants such as Plautdietsch. Indigenous languages and Spanish are official languages of the state according to the 2009 Constitution. The constitution says that all indigenous languages are official, but then defines "all" as 36 specific languages, some long extinct. Spanish and Quechua are spoken primarily in the Andes region; Aymara is mainly spoken in the Altiplano around Lake Titicaca, Chiquitano is spoken in the central part of Santa Cruz and Guaraní in the southeast on the border with Paraguay.