Originally Posted by
dsquared37
Chai means 'correct'. For yes a simple acknowledgement with
krap suffices.
Technically speaking there is no Thai word for yes.
Try uttering
chai after someone gives you directions and see how much it confuses them.

Well, it's just a flavor, which I think is somehow obsolete. Maybe it depends on the region, but my in laws use "chai" to answer questions that require yes/no answer. They use 'ka/krap" more like some sort of confirmation.
I don't think anyone will be confused if a farang uses with "chai" for "yes".