Nheengatu continued to evolve in the 20th century, as it expanded in the Upper Rio Negro region. There was contact with other languages such as Baré, Baniwa, Warekana, Tukano and Dâw (Cabalzar; Ricardo 2006 in Cruz 2015) Due to significant economic and political events such as the Rubber Booms, Portuguese presence was once again felt due to these events, forcing indigenous populations to relocate or into hard labour. Their language, naturally, was once again influenced with the increased presence of Portuguese speakers.