Two important languages of the Moroccan communities in Europe and Morocco are the formal Modern Standard Arabic and Moroccan Arabic which functions as the mother tongue for a large part of the Moroccans. Both languages will be compared from a linguistic and sociolinguistic point of view. The main question in the linguistic study is to what extent both varieties of Arabic show a resemblance, in the domain of the vocabulary particularly. In the sociolinguistic part of the study the focus is to what extent the resemblance between both varieties of Arabic can be applied in the teaching of Arabic, especially in the European context. The results of both studies will also be used for the development of an integrated curriculum for the teaching of Arabic.