In linguistics, "contacto" occurs when speakers of different languages interact, leading to changes in phonology, syntax, and vocabulary. This is particularly evident in , where researchers study how Spanish evolves when it meets other languages:

: In the United States, this contact often results in "Spanglish," code-switching, and the borrowing of loanwords.

From a sociological perspective, "contacto" is a primary tool for social change. The , first popularized by Gordon Allport in 1954, suggests that interpersonal contact between different groups—under the right conditions—is one of the most effective ways to reduce prejudice and stereotyping. Spanish in Contact: Policy, Social and Linguistic Inquiries

: Throughout Latin America, Spanish has been in constant contact with languages like Mapudungun or Quechua, leading to unique regional varieties that incorporate indigenous grammatical structures and vocabulary.