Hello Andres, In English a language is a means of communication but an idiom is a fixed phrase which is a graphic way of saying something. So for example 'to hit the nail on the head' is to get something exactly right. There are lots of them and if you are going to use them correctly you need to learn them well! Best wishes Bob

a language (English) = un lenguaje, un idioma (Spanish) an idiom (Eng) = un modismo (Spanish)