You may have already heard this one, but here goes. Also bare in mind that this is a brain-teaser that can only really be posed audibly (you'll see why) but I'll give it a go anyway. You work as one of these people whose job it is to sit in on court cases and transcribe word for word what the people in dock say. You're typing away when the person in dock says the line, "There are three ways to spell the word to..." Which spelling of to/too/two do you use and why?
Tout...because I'm pretentious and speak French! (Think mange-tout) Seriously, the only question I can think that the barrister would have asked him is "How many ways are there to spell the word to/too/two/tout?" And I'd expect an objection from the opposing barrister on the grounds of irrelevance.
Okay, let's put it another way. One of the characters in the novel you're writing, absolutely must say the same line. Which spelling do you use and why? I think I've found a statement that is impossible to write down word for word.
It's a bit like the statement "I always lie." Because, if I always lie, I'm lying about always lying... In the same way, there is only one way to spell "to", one way to spell "two", etc. If I absolutely had to have the line There are three (or four) ways to spell "to", then I agree with @Aaron DC , just use "to". Incidentally, does the "tu" of "tutu" count as a fifth way?