[8] The enlargement of the European Union over several decades gradually diluted the influence of two of the EU's other non-English working languages of German and French.
The development of the international student exchange Erasmus Programme, an open borders travel policy establishing the Schengen Area, and the establishment of a customs union created a new class of mobile young people in Europe who needed a lingua franca to communicate across Europe, and English usually filled that role.
[11] Although these young mobile Europeans had a greater potential to shape a continental norm, they appeared to use English mostly for pragmatic reasons rather than as a language they strongly identified with, and there was still not enough evidence to conclude Euro-English constituted an independent variety.
[11] Euro-English was heavily influenced and dominated by British English, due to the United Kingdom's having been an EU member state between 1973 and 2020.
However, the UK's withdrawal in early 2020 means that the EU's scope of native English dialects has been mostly reduced to the varieties of Hiberno-English spoken in the Republic of Ireland; one source believes that this will allow room for Romance languages to have more of an influence on Euro-English.
[20][21][22][dubious – discuss] This mirrors the usage of "singular plurals", in terms of levels of formality, in European languages, such as French vous, German Sie, older Spanish vos, Danish and Norwegian De, even though all of these examples are strictly used in the second person.