Tone sandhi occurs to some extent in nearly all tonal languages, manifesting itself in different ways. Tonal languages, characterized by their use of pitch to affect meaning, appear all over the world, especially in the Niger-Congo language family of Africa, and the Sino-Tibetan language family of East Asia, as well as other East Asian languages such as Tai-Kadai, Vietnamese, and Papuan languages. Tonal languages are also found in many Oto-Manguean and other languages of Central America, as well as in parts of North America (such as Athabaskan in British Columbia, Canada), and Europe.