Tests in 14 countries of the 27 EU countries showed only 42 per cent of teenage pupils competent in a first foreign language and just one out of four able to converse in a second foreign language, a the European Commission report showed.
"We must do more to improve the teaching and learning of languages," said education commissioner Androulla Vassiliou. "Being able to communicate in a foreign language broadens your horizons and opens doors."
The worst offenders are in Britain, where only nine percent of teenagers are competent in French, followed by France, where just 14 per cent of students of English can hold their own in a conversation.
However Malta and Sweden score well. English in both countries is the first foreign language and a huge 82 per cent speak it well enough for a conversation.
Though 53 per cent of Europeans use languages at work and 45 per cent believe foreign language skills are important to get a good job, the number of Europeans who say they can communicate in another language has dropped slightly in a decade, from 56 to 54 per cent, according to a separate survey, by the EU pollsters Eurobarometer.
Its thought this was partly due to the fact that Russian and German were no longer compulsory in schools in central and eastern Europe.
Countries showing the most notable increases since 2005 in the number of people saying they are able to speak at least one foreign language were Austria, up 16 points to 78 per cent, Finland, up six to 75 per cent and Ireland, also up six to 40 per cent.
The five most widely spoken foreign languages remain English at 38 per cent, French at 12 per cent, German at 11, Spanish with seven per cent and Russian at five per cent.