Multilingualism is when the people are able to use more than two languages in their everyday life or when more than two languages co-exist and are necessary in everyday communication.
The languages they use have different statuses as majority/minority languages both in their community and internationally and some of the languages are used primarily in the private domain while others are used primarily in public domains, such as work or school.
Is the development of multilingual competence with the help of the educational system.
Trilingual/multilingual education consisted in educational programmes that use languages other than the first languages as media of instruction and they aim for communicate proficiency in more than two languages.
Multilingual education can take different forms because it is necessarily linked to the sociolinguistic context in which it takes place and has to take into account the relative status and use of the languages involved.
-Common underlying proficiency
Some linguistic proficiencies are common to all languages used by learner
Abilities needed to communicate are not linked to a specific language
CUP is not innate: it is established and evolves while learning to use language(s)
The more languages you learn, higher your ability to represent world and communication
Result: ability to learn languages from the ones you already know
Diferences additive and subtractive bilingualism
In additive bilingualism the first language continues to be developed and the first culture to be valued while the second language is added. Linguistic knowledge is integrated and there is a bi-directional transference across languages.
While in subtractive bilingualism the second language is added at the expense of the first language and culture, which diminish as a consequence