Whoa! vs Woah!

I think you would say "Whoa!" to a horse

When spoken in human company, "whoa" (as I've heard it used) expresses surprise, but it also carries with it the implication of "slow down and give me a moment to absorb that".

it also carries with it the implication of "slow down and give me a moment to absorb that".

sometimes it does. but it can also mean "no no, stop that!", whether to a horse or to another person. i'm thinking back to various times in my life when i have witnessed something horrible that should immediately stop. it's tough to recall particulars, but i remember shouting variants of "whoa whoa whoa no! no!"

Big Don Afterthought going full Sidney Powell

"whoa" may be a more generalized word for me, though - almost more like a sound or a feeling, sometimes. whoa flies out of my mouth left and right, in many contexts