Language is one of the fundamental features of the identity of individuals and groups. As a social phenomenon has two basic functions: communication and identity.
On the example of the Czech minority in Croatia, we strive to observe factors that acts on language retention in ethnic minorities - besides commonly referred to (such as administrative and legal status and ensuring the rights of the minority language, family, minority education, news in the minority language, religion, cultural activities, etc.) we observe the effects of choice of life partner, living together in one household with other people, knowledge of language and language interference, employment and liberal education.