I read that when using a future tense, œwill expresses a willingness, œgoing to expresses a prior plan, and either is used for predictions¦interesting and a little confusing given how often we interchange the verb¦it makes me wonder if the best way to figure out which verb to use is to substitute the word œintention.

Why did you buy the crate?  I’m going to buy a dog (as in, I’m hoping to buy a dog) versus I will buy a dog (as in  it’s my intention to buy a dog)¦

To be honest, this all seems very confusing”especially in predictions: Watch out! You’ll lose an eye versus Watch out! You’re going to lose an eye!

Ditto with expressing a plan versus willingness¦if I’m going to shop tomorrow or I’ll shop tomorrow, it seems like the same thing to me¦

Anyone have an answer to this conundrum?