Comment by handsclean

Oh man, I didn’t know other people did this, I invented it in my friend group. Never in proper writing, only texting. To me it conveys a tone that other punctuation can’t replicate. For example:

Ok.. - Ok, but I’m unsure about this

Ok - Ok

Ok… - Ok, but I’m sad or resigned about this, and I want you to address that

Ok. - Ok, and that’s final

Ok? - I don’t know why you’re saying this, explain yourself

Ok…? - I don’t know where you’re going with this, explain yourself

Even writing “Ok, but I’m unsure about this” isn’t the same, because that calls more attention to your hesitation. If you don’t use “..”, your only alternative is to spend a minute basically doing translation work between inflected English and monotone English, maybe arriving at something like “Ok, I’ll try”, or more likely just give up and communicate in lower fidelity.