Only a fifth of 15-year-olds now learn a foreign language, a survey published today shows.
Headteachers blame a lack of high-quality language teachers and say uninspiring lessons are putting teenagers off. The Government's decision to make the subject non-compulsory is only partly at fault.
The survey by the Secondary Heads Association highlights the sharp drop in take-up of modern languages since the Government made the subject non-compulsory for over-14s a year ago. Its findings are more alarming than a survey last November by Cilt, the National Centre for Languages, which suggested that more than a third of teenagers were abandoning languages.
One anonymous head said: "Students opt out of MFL (modern foreign languages) here due to the quality of teaching in comparison to other subjects available. I believe that numbers would be appropriate if the quality was on a par with other subjects."
SHA surveyed more than 150 schools to find out how their take-up and staffing for languages had changed at key stage 4 over the past two years.
It found that an average of just 20 per cent of Year 10 and 31 per cent of Year 11 pupils were still studying modern languages.
The association also discovered that the average number of fulltime-equivalent language teachers in secondary schools had fallen to five - down by 5 per cent .
If replicated nationally, this would suggest around 1,000 language teachers had left their jobs in the past two years - one for every three secondaries - at a time when qualified teacher numbers have been increasing.
Several headteachers, who gave comments anonymously, criticised the Government's decision to make languages optional or deplored the lack of interest in the subject among teenagers.
"The declining numbers of MFL students are a reflection of the insular attitudes of many of our parents and students, which recent government policy has made much worse," one wrote.
The dwindling supply of good language teachers was seen as an even greater worry.
One head wrote: "The Government's wheeze of cutting back on MFL is an attempt to hide the fact that there is a dearth of MFL teachers. And it will get worse."
Schools which had succeeded in hiring language teachers complained that their lessons were often uninspiring and unpopular. Some noted that behaviour could be poor in the classes and that there were "cultural issues" when they employed French-national teachers.
Sue Kirkham, SHA president and a former languages teacher, said: "I am concerned by the figures but not entirely surprised because it is what we expected would happen when they ended compulsion at KS4.
"The perception in schools seems to be that it is harder for pupils to get good GCSEs in modern languages and when pupils have a choice they are not choosing them."
A DfES spokesman acknowledged that there had been a drop in pupils studying languages at KS4. But he said: "Over time, with languages being introduced from the age of seven, we will move to a situation where young people choose to study languages rather than being forced to do so."