gerunds and frapps

::: through a bulletin notice i saw at one of kobe's international centers, today i met yoon at starbucks...

...yoon is a recent graduate of kobe university's mba program...a native korean but fluent in japanese, yoon is busy interviewing w/ top-level companies and studying english for professional placement...he's 29, a newlywed (he's been friends with his wife since both of them were 6yrs old), an eager-beaver, and an all-around pleasant fellow...

...why did i decide to meet him?...first, as i help him with his english, he's teaching me japanese (and korean!)...second, it has been difficult to strike up friendships with japanese college and post-college guys who are around my age...this is a good way to do just that...with gospel hope i anticipate meeting yoon every wed...

...but speaking english and teaching it are two separate things...i realized the latter is going to be very challenging...while sipping frapps, yoon's first question to me was the following: can you explain the specific rules for using a gerund vs. an infinitive?...yikes...thankfully i like grammar in a strange sort of way...