Jolkesky (2016) notes that there are lexical similarities with the Arawa, Bora-Muinane, Guato, Irantxe, Jivaro, Karib, Kayuvava, Mura-Matanawi, Taruma, Trumai, Yanomami, Harakmbet, Katukina-Katawixi, Arawak, Bororo, Karaja, Macro-Mataguayo-Guaykuru, Takana, Nadahup, and Puinave-Kak language families due to contact.

[2] When the Portuguese arrived in Brazil, they found that wherever they went along the vast coast of South America, most of the indigenous peoples spoke similar languages.

Jesuit missionaries took advantage of these similarities, systematizing common standards then named línguas gerais ("general languages"), which were spoken in that region until the 19th century.

In the neighbouring Spanish colonies, Guarani, another Tupian language closely related to Old Tupi, had a similar history, but managed to resist the spread of Spanish more successfully than Tupi resisted Portuguese.

Meira and Drude (2015) posit a branch uniting Mawé and Aweti with Tupi-Guarani, also known as Maweti-Guarani.