Education watchdogs have called for changes in the way modern foreign languages are taught to reverse a declining trend in pupils taking exams.
There were 700 A-level language entries in 2015 compared with 1,152 in 2009.
It found a fall in the use of the language as the means to instruct pupils, with teachers using English.
The report, Modern Foreign Languages, partly blamed core curriculum requirements and limited option choices for a decrease in the number of students taking GCSE and A levels in languages.
Estyn's report looked at the quality of teaching and learning since its last report in 2009.
And while it found "adequate" teaching standards, it said much time was taken up in writing grammatical exercises where "learners lose interest" rather than speak the language itself.
Estyn's chief inspector Meilyr Rowlands said: "Too many learners, even the more able, do not speak a modern foreign language fluently."
The report found:
- Grammar and written exercises were often prioritised over speaking and listening
- Preparing conversation topics in writing and using English to explain "even simple class instructions hinders pupils from developing real-life fluency"
- Typically learners get three hours of modern foreign language learning across a two-week timetable - less than the two hours a week recommended
A Welsh Government spokesperson said: "We are working with key partners, including language institutes and universities, to arrest and reverse the decline in the take up of modern foreign languages.
"Languages play an important part in a learner's curriculum, which is why last year we published Global Futures - a five-year plan to improve and promote modern foreign languages.
"The plan sets out how we aim to increase the number of young people choosing to study modern foreign languages at GCSE and A-level.
"It also sets out our ambition for Wales to become a 'bilingual plus one' nation, where every learner will study English, Welsh and at least one modern foreign language from Year 5 onwards."