By vs. For vs. To

[PVTravel]

My students asked me to prepare a short lesson explaining the differences between to, for and by. Now of course I know how to explain them individually but I am not sure how to explain all three of them in relation to each other. Any advice?

[Rover_KE]

Welcome to the forum, PVTravel.

You're not being ignored. We're beating our brains trying to figure out how to answer this question.

I for one have no idea how to relate these prepositions to each other.

Rover