Migrations have always been instrumental in bringing about contacts among different peoples speaking different languages. Quite often, groups of migrants have managed to retain their cultural and linguistic identity amidst a larger population, to retain ties to their area of origin, or to maintain a network of contacts with other groups of similar origin or affiliation, giving rise to what has become known as 'diasporas'.

In the world of globalisation, it has become to some extent easier for migrating groups to maintain diasporic identities: Ease of travel and communication support continuous contact with origin communities, as well as with other affiliated communities of migrants, and allow to maintain culture and language independently of sharing space or territory. Language and culture have become, in this respect, 'de-territorialised'.

Yet diasporic identities are not monolithic. They are often composed of layers of features, some inherited from a place of origin, others developed within the community after migration, and others still adopted from surrounding populations. Diasporic cultures are typically a mosaic of features. They are essentially 'hybrids'. This applies to language as well. Linguistic minorities especially display linguistic hybridity in several respects: Individuals tend to be multilingual, using different languages for different purposes. Conversations often draw on more than a single language, as bilinguals make use of switching from language to language for special effects. And finally, language itself absorbs influences from other languages, leading potentially to language change.

These aspects of linguistic behaviour and structural change in language in multilingual settings are the subject of investigation of contact linguistics: How are different languages used in the community and by individuals? How are multilingual conversations structured? And how does language change as a result of contact? The study of language contact is thus the study of hybridity in language.