Resources for learning english

I know /lang/ is about foreign languages, but I figure you guys would know this.

I'm wondering if /lang/ knows good resources for me to help teach English to my language exchange partner, who's currently at about upper intermediate level. I ask because (1) I may be missing out important stuff (2) it's difficult explaining some of the rules which just come naturally.

it may be easier if you can explain in their language.
try different levels of school text books.

hola me gustaria saber si a alguien le gustaria hacer un videojuego conmigo, gente que sepa un poco de 3d o programacion en c#.
diganme algo por fa

瑞贝斯英语 : http://www.reebess.com