Miggy
Just a thought to throw into the pot. Might it be that he just doesn't enjoy/like French? Only reason I ask is that sometimes we just never learn much of something we have little interest in, no matter how long we have studied it.
I did French and Latin in Yr1 and Yr2 of Secondary School. Could do French quite well, but did not enjoy it. Latin, I loved (strange, I know), possibly because of all the associated History that was part of the subject and which was learned alongside the language (this didn't seem to happen with French, probably because it is a modern language being taught on a 'everyday words' basis). Is your son keen on History?
Anyways, basically, I dropped French and continued with Latin for another 3 or 4 years (also, probably connected to my enjoyment of Latin and like of History, I took up Greek (Ancient) and studied that for about 4 years).
Both languages I did well at because I enjoyed them and the associated History - this, in my experience, made the difference. Yes, they are pretty useless languages nowadays, as people have joked, but so are a number of things we learn in other Subjects (how many of you use all the knowledge you gained in maths, enlish, R.E, Economices, history, geography etc., etc, on a daily basis?). Mind you, I had to 'fight' to drop French (did Art in place of it) and was frowned upon for wanting to do Greek (had to drop Science). Wouldn't have minded doing Greek and Science but Subject clashes in those days were very common and something had to give.
Sometimes we focus so much on what we think is right and proper for people to study that we forget to ask what they actually enjoy studying.They then struggle and push themselves to achieve in Subjects they 'hate' whilst all the while a Subject they could excel in has been pushed to the side. Off topic slightly, but just think of the pressure so many kids are put under nowadays to achieve - perhaps the pressure would be lessened if they were allowed to follow their instincts more and do Subjects they liked.
Oops, sorry if I have rambled on, hope it makes some sense though.
butterfly
(who also has had lovely holidays since enjoying all that 'Roman - Greek' history)