Exam boards have written to schools and colleges this month asking for details of what subjects students plan to continue with in upper sixth.
Many are still in the dark about pupil choices and will not have firm numbers until the first set of AS-level results come out in August.
But, according to the Association for Language Learning, students are pulling out of a second year of language study.
Stephen Fawkes, association president, said: "It was hoped that AS would broaden what students study and provide a language course not too far from GCSE, thereby encouraging more pupils to take full A-level. It has not worked out that ay.
"AS syllabuses have thinner content but the grammatical demands are the same. It is like a two-year course crammed into nine months." At Colchester sixth-form college the number of French and German classes will be cut by half next year.
Clive Sheldon, head of modern languages at Trinity school, Carlisle, said that AS language courses were seen as more difficult than those in other subjects.
He said: "Many language sets look likely to go from small to non-viable as students choose their three 'easiest' subjects, dropping the language. It is no surprise that many schools will have seen a surge of interest in psychology, sociology, media studies, drama, environmental studies and art because students are eager to try something new or a subject perceived as more practical or less academic."