The notion of metalanguage it is used in two different domains. In the field of linguistics, the term refers to language used to refer to another language, while in the computing the concept refers to the language used for description of a programming language system.
As can be seen, beyond the differences given by the context, there is a great similarity between both definitions. The metalanguage is always a language (a mode of expression through a set of rules and signs) that speaks of another language (called target language within the framework of this relationship).
Sometimes the metalanguage is the same as the object language: this happens, to cite one possibility, when appeal is made to the English to refer to it English. A metalanguage, on the other hand, can act as an object language in a different link.
Focusing on linguistics, metalanguage is the result of a function adopted by a tongue natural. The linguistic code, in this way, is taken as the object of the utterance. In other words: metalanguage is a language used to describe the language.
Let’s consider the sentence “Salir is an irregular verb”. In this case, the verb “get out” It is used with a metalinguistic function, since it describes linguistic properties. There is a use, therefore, of the metalanguage.
Other types of metalanguage are models of syntax used to describe grammar; a clear example of this is the generative grammar, a series of theoretical frameworks that allow studying the syntax of languages, by means of various principles or rules that help to correctly predict the combinations that may appear in a correct sentence from a grammatical point of view, for a given language.
The term metavariable is defined as a symbols or several in a chain that serve to represent certain elements of an object language. They belong to the metalanguage and can be seen in the following example sentence: “If A and B are two prepositional verbs, then C is not”. Here we have three metavariables expressed by using letters that represent verbs of different types.
It is important to respect the meaning of oneself variable within its context, that is, do not use it for another purpose until the speech is over. In the field of education, both for children and adults, the use of metalanguage and metavariables is almost essential in many of the subjects, since they allow a certain degree of abstraction, necessary to establish knowledge in a general way.
In many cases, we use the metalanguage resource without realizing that we are generating potential confusion in the interlocutor, as can be seen in the following sentence: «Acute is every word that is stressed in its last syllable. But ‘sharp’ is not sharp. In this confusing example, when the word is enclosed in quotation marks it is mentions while in the other, it uses.
This answers the call distinction between use and mention belonging to the fields of the logic, grammar and philosophy. When uses a word refers to the object of its meaning; when it is mentioned, however, it is nothing more than a dictionary entry, framed in one or more classifications but without a representation in the real world.
In the case of proper names it is easy to distinguish the use (“Pedro is coming to dinner tonight”) of the mention (“The word ‘Pedro’ has five letters”).
In computing, a metalanguage is used to say something about another language. An example is XML, metalanguage that defines languages such as MathML and the XHTML according to the needs.