Language is a system that consists of the development, acquisition, maintenance and use of complex systems of communication, particularly the human ability to do so; and a language is any specific example of such a system.
A modern language is any human language that is currently in use. 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 or 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 § Linguistic diversity).
Henry Drummond: Language is a poor enough means of communication. I think we should use all the words we've got. Besides, there are damned few words that anybody understands!
Inherit the Wind (1960 film), Jerome Lawrence and Robert Edwin Lee