My poor children are trying to learn French the National Curriculum way. This approach seems to rely fundamentally on the principle: "Don't mention grammar!" It's little wonder that English people are so bad at languages, because we aren't ever taught how they work.
So they learn lots of phrases and bits and pieces. You can say, "J'aime le sport. C'est génial!" from a pretty early stage. But nobody tells you that "j'aime" is part of the verb "aimer", which if you want to, you can do an awful lot more with. And even more frustratingly, nobody ever seems to say anymore: "être, avoir, faire, aller - these are four irregular verbs which will take a little while to learn, but once you have got to grips with them, you will actually be able to communicate a huge range of ideas." This represents about four lessons' worth of learning - but would do more to make people confident in basic French than three whole years of learning phrases about liking Coca Cola and going to the park to do sport tomorrow.
Of course, if you are immersed in French culture, then you learn fast - by trial and error - starting from a relatively small vocabulary. That's how children learn language at home. Think of the mistakes that we make as children - "brung" instead of "brought", "buyed" instead of "bought", "goed away" instead of "went away". The reason that those mistakes are made are because we are trying to apply rules we have intuitively picked up too simply to the language - not because we have no awareness of them. As we grow, our stock of rules grows, and we become more adept at using language.
But children learning a second language simply aren't in an environment where they have the ability to try out different rules they have intuitively worked out. So they just end up with the stock of a few hundred basic phrases, all individually learnt, all with no connection to each other. It's SOOOO much harder to learn that way, and it's hardly surprising that the whole lot has been dumped by the time the child is 17.
My recommendation for the government? It doesn't make any difference how young you start teaching a foreign language, if you aren't teaching it in a way that corresponds with how people's minds work. Literacy levels in primary schools have risen since the National Literacy Strategy was initiated - to the extent that many children go to secondary school with loads of English Language concepts that they simply don't need through GCSE. Unsurprisingly, children tend to "go backwards" educationally in year 7, which I think still hasn't been adapted to deal with the ground that is covered in Key Stage 1 and 2. If you want people to learn foreign languages, find better ways of teaching them. By all means teach vocabulary and phrases to primary children. But if you want secondary children to really learn languages, then for goodness' sake teach them how the languages work!