Were you ever curious where Miyamoto picked up his English skills? It turns out the responsible party is Dylan Cuthbert, creator of Star Fox, president of Q Games and one of the best-known Westerners to get in good with Nintendo.
When he was featured in the most recent Iwata Asks, he revealed that the two taught each other their native languages when he first started working with the company. Cuthbert would speak in Japanese to Miyamoto and Miyamoto would speak in English to Cuthbert, having a bit of trouble with his prepositions along the way.
Cuthbert also stated that he originally impressed Nintendo at age 18 with his 3D Game Boy engine, and that he will direct the upcoming Star Fox 64 3D.