I agree, both with -aggie- and simsaladimbamba's recommendation of Monolingual, and -aggie-'s recommendation to be careful when using it. Removing the wrong architecture or language can have adverse effects on your Mac's operation. Also, if you have Garageband and you're not using it, you can move the loops to an external drive (don't just delete them, as you may decide you want them later). I'm assuming you have most of your user data stored on an external drive already.