We suggest a demand model for foreign languages and estimate demand functions for English, French, German and Spanish in 13 European countries. We show that three variables explain reasonably well the share of people who learn a foreign language: the larger the native population in the country, the less its citizens are prone to learn another language; the more the foreign language is spoken, the more it attracts others to learn it; the larger the distance between two languages, the smaller the proportion of people who will learn it.