the reason when/te reason why/the reason for why

[englishhobby]

Are all the sentences below correct and natural?

1) What was the reason for why Amy didn't talk with her dad for days once?
2) What was the reason why Amy didn't talk with her dad for days once?
3) What was the reason when Amy didn't talk with her dad for days once?

 

[GoesStation]

They are all unnatural. If you want similar wording, I'd say "What was the reason Amy once went for days without speaking to her dad?" More succinctly, "Why did Amy once go for days without speaking to her dad?"

 

[Raymott]

1) What was the reason for Amy['s] not talking with her dad for several days one time?
But I like GS's last one.

 

[tedmc]

I think OP's sentence could meant either "Amy did not talk once to her dads for days" or "Amy did not talk to her dad for days once(on one occasion).

 

[Raymott]

That's unlikely, ted.

 

[Tdol]

1 is plain wrong to me- don't use reason for why.