First of all, it should be remembered that all languages must be considered as a resource belonging to the learner's heritage and a support for learning, particularly when learning the language of schooling. Non-written languages (dialects, vernaculars, etc.) are languages like any other, and like any other, they are useful and usable in class.

Thus, any language used in the learner's family circle can be a basis for language learning, particularly the learning of the language(s) of schooling. So it is important to be able to assess and measure competences in these language, whatever they may be, in order to acknowledge them, build on them and continue to develop them.

The aim of encouraging learners (particularly migrants) to maintain their first language and their home languages in general is not only to continue the process of learning these languages but, by encouraging the transfer of competences and knowledge, also to develop competences in learning how to learn (languages), which can support the development of competences in the language(s) of schooling.

Since Cummins’s work (2000), changes in the teaching-learning model have included adding the languages of learners' home environment to learning objectives. In order to find more effective ways of extending the use of the target language beyond the classroom, learners look at and work on it in various tasks that focus on the language(s) in their own repertoires. Becoming aware of and developing a positive relationship with the role of one's home language(s) help learners in important ways to fully develop their language competences.

This is why it is important to emphasise that, when learners learn a new language, all the languages/varieties in their repertoire are involved and can be used. It is therefore important in education to reinforce the natural dynamic of bi- and plurilingual learners’ language development in order to help improve their academic success and to ensure greater equity (Reich and Roth, 2002: p. 42).

As a result of different migration backgrounds, many learners today grow up knowing several languages which they have acquired or learned at school and in extra-curricular contexts. The school's mission is to enhance the linguistic, communicative and intercultural competences of these learners and to recognise their potential. The diversity of languages corresponds to a broad linguistic range. Taking a global approach to language education enables learners to develop their competences in their home languages step by step and to continually broaden them as they progress through the levels defined by the syllabus frameworks. It also enables them to assess their own level of learning.

Unesco believes that everyone has the right to learn in their own language, and that this is an important means of improving their learning, their learning achievement and their social and emotional development. But on a global scale, cultural and linguistic diversity also plays an essential role in the development of sustainable societies and contributes to strengthening peace, tolerance and respect for difference.

With this in mind, the right of learners to learn the language(s) of schooling with the support of their home languages can be envisaged.