After ds1 failed to cover himself in glory in his end of y8 Spanish exam (didn't do terribly, but lost loads of marks on basic grammatical errors), I feel he needs to spend just a small part of his 9 week holiday (yes, NINE WEEKS ) on getting to grips with the language.
Can anyone recommend good resources (books or web-based) which he can work his way through in a structured manner, and which will be reasonably appealing to a 13 year old boy (i.e. he really doesn't need to know how to buy a house in Spain!). He has access to Linguascope's website through school, but he doesn't need endless vocab games, his vocab's fine-ish - it's really grammar that I'm after.
suggestions very much appreciated