Some secondary school foreign language teachers are "unprepared" to use the language in class, a report by the education watchdog has found.
The report, Modern languages - Achievement and challenge 2007-10, released by Ofsted, recognises the significant efforts made to support languages - especially in primary schools - since the watchdog's last languages report in 2008.
But it also highlights a number of weaknesses in the way secondary students are taught.
The report states: "In many of the secondary schools visited, opportunities for students to listen to and communicate in the target language were often limited by many teachers' unpreparedness to use it.
"Too often, students were not taught how to respond to everyday requests and thus routine work in the target language and opportunities to use it spontaneously were too few."
The report also found that in 33 of the 90 secondary schools inspected, reading was not taught beyond exercise books and that teaching focused on achieving good exam results.
Some secondary schools were failing to build effectively on the progress made by children at primary schools, which were found by Ofsted to be making "good progress" in teaching foreign languages.
Christine Gilbert, Her Majesty's chief inspector, said: "Young people can gain tremendously from learning an additional language, acquiring invaluable skills for their lives ahead, so it's good to see the progress made in our primary schools over the last few years.
"However, too many students are failing to reach their potential and do not choose to undertake more advanced study beyond 16 because of the way they are taught languages in many secondary schools."
Since languages were made non-statutory in 2004, the proportion of students at Key Stage 4 taking a language qualification has gradually declined from 61% in 2005 to 44% in 2010.