Today the majority of adults in France will have done betwen 5 and 12 years of English at school. Their English classes will have invariably focused on grammar and on written work in class. There will have been realatively little speaking practice.
Hence many students will have a good basic (and even quite advanced) knowledge of grammar rules and terminology but will feel quite uncomfortable and ill at ease when having to speak English.
The larger part of adult students taking English classes will be doing so primarily for work reasons. English is becoming a more and more an indispensable tool in business - businesses that were dealing exclusively with the French market are now turning more and more to an international market. Many students today clearly state that a good operational level of English is vital for their future career development.