Definition of grammar

Grammar is the science that studies the elements of a language and its combinations. The concept derives from the term latin grammatĭca and means, on the other hand, the art to speak and write a language correctly. Grammar is therefore the set of rules and principles governing the use of a specific language (each language has its own grammar). As a science, it is part of Linguistics.
The study of the language consists of four levels: the level of phonetic and phonological, syntactic and morphological lexicon level – and semantic and pragmatic level. Although the separation between these levels is not accurate, it tends to be restricted to the study of grammar at the syntactic and morphological levels.
Among the many types of grammar or approaches to the study of grammar, there is mention prescriptive or normative grammar (it presents, in an authoritarian manner, standards to use for a specific language while despising the non-standardised constructions), descriptive grammar (it describes the current use of a language, without judging prescriptive way), traditional grammar (ideas concerning grammar inherited from the Greece and Rome) , functional grammar (a general vision on the Organization of natural language), generative grammar (a formal approach on the syntactic study of languages) and formal grammar (which appears in computational linguistics).
The french, for example, is a so-called Romance language whose grammar is rich in time and modes, although more orally and in writing. On the other hand, some plurals and some people in the conjugation are most notable in writing.