The audiovisual sector also faces competition from Hollywood productions, and the share of admission to EU films on the world market is very low. Very few European feature films make it to the top 10 or 20 on the EU box office list. US films account for almost two-thirds of the EU film market, while EU productions, together with co-productions with the US, represent just one third. Moreover, the circulation of non-national EU films that are not co-productions is difficult. This is due, among other things, to linguistic barriers, which raise the costs of international distribution. Between one- third and a half of EU citizens do not speak a foreign language, and cannot follow non-national content, making translation and subtitling necessary for the successful circulation and distribution of cultural works. The most popular foreign languages taught in schools are English, French, German and Spanish, which are also among the most widely spoken mother tongues. But there are 20 other official EU languages to consider.