Up here in the North or in Chiang Mai, speakers say, “sà wát dii jâo”. Normally it’s the women who say “ jâo” You might also hear “wàt dii” which is what I equate to as the English equivalent of “hi”. In other words, it’s just a shorter version of “sà wàt dii”.And if you’re really lazy (or efficient) like me, you’ll just respond to sà wàt dii, by saying “kâ”.