A mixed language is a language that arises when two languages are in contact and there is a high degree of bilingualism among speakers. (Occasionally, more than two languages may be involved.) A mixed language differs from a pidgin in that its speakers are fluent, even native, speakers of the languages involved in the mixture, whereas a pidgin develops when one group of speakers has only a rudimentary knowledge of the other language. A mixed language differs from a creole in that a mixed language has not evolved from a pidgin, while a creole has. A mixed language may be said to evolve from persistent code-switching and indeed language names like "Spanglish" are often given to persistent code-switiching long before it is clear that a genuine mixed language has evolved. Other apparent mixed languages, such as Franglais and Yinglish, are really nothing more than names given to varieties of a language (like French and English respectively) characterized by large numbers of loanwords from another language (like English and Yiddish respectively).

The best example of a genuine mixed language is probably Michif (a mixture of French and Cree). Other possible examples include:

• Wutunhua (a mixture of Chinese and Tibetan)
• Yeniche (a mixture of German, Yiddish, and Romani)

In addition to Spanglish and Yinglish mentioned above, there are many varieties of English that are distinguished from "standard" varieties by being in contact with other languages. These may not be genuine mixed languages, but rather cases of persistent code-switching or heavy loanword use. They include:

• Englog (Filipino/English)
• Finglish (Finnish/English)
• Franglais (French English)
• Germish (German/English)
• Hinglish (Hindi/English)
• Konglish (Korean/English)
• Madras bashai (Tamil/English)
• Manglish (Malay/English)
• Nuyorican (Spanglish as spoken by Puerto Ricans in New York City)
• Runglish (Russian/English)
• Swenglish (Swedish/English)
• Taglish (Filipino/English)
• Thailish (Thai/English)
• Vinish (Vietnamese/English)
• Yanito (Spanglish as spoken in Gibraltar)
• Yeshivish (Yinglish as spoken by Yeshiva students)

Similar names are given to "broken" English found in foreign countries, for example:

• Chinglish (Chinese/English)
• Dunglish (Dutch English)
• Engrish (Japanese English)

These are simply non-native uses of English and cannot be considered mixed languages.