The study reveals "a degree of mismatch in the provision of teachers and classes in some authorities". This is despite the fact that 4,500 teachers have gone through the 27 days of training since the initiative was established in 1993, compared with an initial target of 2,755 teachers.
The study, by Daniel Tierney and John De Cecco of Strathclyde University, reports that 95 per cent of primary schools had at least one trained teacher by the end of last session. Its findings are based on returns from a remarkable 94 per cent of schools.
The report to the action group says schools must ensure that all pupils are involved in foreign language learning at the primary 6 and primary 7 stages. There must be an adequate supply of trained teachers, the researchers state, and their linguistic competence must be sustained.
The importance of ensuring that pupils continue with the same language when they move from primary into secondary is also stressed.
One Edinburgh primary reports "several fundamental problems" with the programme, regarded as a cornerstone of Government policy. "Where children are leaving primary and going to a range of secondary schools, it is often not possible to prepare them in the appropriate language. Secondly, timetabling teachers to teach classes other than their own is often problematic, particularly in relation to continuity."
Other schools cite problems ranging from an overcrowded curriculum to patchy expertise among teachers, and point to the need for refresher courses to bolster initial training and the addition of modern languages to pre-service courses.
Questionnaires returned from 2,143 primaries show that 3,922 teachers have been trained over the past six years, 77 per cent of them in French. There were some notable variations - 17 per cent of East Renfrewshire teachers were trained in Italian compared with the Scottish average of 1 per cent, while 16 per cent of those in East Ayrshire were trained in Spanish against a national figure of 3 per cent.
The highest proportion of German-trained primary teachers was in Fife - 40 per cent against the 19 per cent average.
Despite assumptions, however, only 627 of the 3,922 teachers trained since 1993 have been lost to modern language teaching either through promotion, retirement or transfer.
The findings reveal that pupils in rural areas are getting an earlier start to learning a foreign language, although that is largely thought to be because of the number of schools with multi-age composite classes. Nationally, only 26 per cent of primaries say modern languages are being taught from primaries 1-5, a figure which rises to 60 per cent in Highland and 53 per cent in Dumfries and Galloway.
Pupils are mostly taught by their own teacher, although 36per cent of schools arrange for teachers to "swap" their classes with the foreign language specialist. The report says this has proved to be a successful way of deploying teachers.
The average time spent on languages in primaries is an hour a week, with some pupils doing 20 minutes and others two hours.