By asking "Qu'est-ce qu'un trou noir?" rather than "Ou est le chien noir?", children should be able not only to remember science but also to memorise French vocabulary and sentence structure.
That is the hope of Catherine Cheater, a language-teaching consultant pioneering this method of teaching primary French by linking it to other areas of the curriculum to prevent children from becoming bored.
Ms Cheater, a co-author of the key stage 2 framework in languages, said:
"Asking questions and hearing answers about the universe is something more grown-up for children than asking for lemonade. They learn to ask 'What is a black hole?' and 'Will the sun disappear one day?' and they can understand the answers. The topic also has lots of words which sound similar to English words - it is not difficult to guess the meaning of 'geante rouge'."
More than 40 authorities are already using Ms Cheater's Year 3 and Year 4 resources. A new set for Year 5 is published today.
As well as linking to science, the Year 5 scheme focuses on healthy French food and an introduction to the artists Gauguin, Manet and Pissarro.
Authentic resources are used where possible, including translations of Tony Ross's Little Princess books.
The cross-curricular approach could soon be mirrored in secondaries. Last week the Qualifications and Curriculum Authority proposed letting pupils choose their topics for GCSE languages, after criticism that content was too dull.
* The Catherine Cheater Schemes of Work are published by Teaching and Learning Publications, www.tlpubs.org.uk