A modern language is any human language that is currently in use as a native language. The term is used in language education to distinguish between languages which are used for day-to-day communication (such as French and German) and dead classical languages such as Latin and Classical Chinese, which are studied for their cultural and linguistic value. SIL Ethnologue defines a living language as "one that has at least one speaker for whom it is their first language" (see also Language ยง Linguistic diversity).
Modern languages are taught extensively around the world; see second language acquisition. English is taught as a second or foreign language in many countries; see English language learning and teaching.
International auxiliary languages are by definition not associated with a particular country or geographic region. Esperanto is probably the best-known and most widespread. Interlingua, a much less popular, but still growing auxiliary language, is likewise spoken mainly in Northern and Eastern Europe and in South America, with substantial numbers of speakers in Central Europe, Ukraine, and Russia. Constructed languages from more recent years with sizable user communities are Klingon, Toki Pona and Interslavic.