anything = a choice Although I know everything, I can only do one thing at a time, so I must choose. = I can do anything. If talking about the past then you must say: "I did everything." As you can see, you must also say: "I taught him everything." If you are offering a lesson, then you can see: "I can teach you anything (you like)." See the choice here?

it doesn't fit cuz you the daddy. you should have taught your son. deadbeat dad?! lol

Every = Means all, always. Any = Means an variable amount of something. it could mean 0 as much as it could mean 10000. I don't have ANY money. You can have ANY of these toys.

everything = all his knowledge anything = doesn't state how much or what he taught his son I can do anything.( it implies that he can do everything)