For instance if a child wais an elder, a waitress wais after receiving a tip or a junior employee wais for his boss, the wai will nor be returned. Instead the answer might be a smile or a nod. When and how to wai comes very natural for Thais since it's learned from very early childhood. For the visitor however, it can be a big problem to get the correct wai at the correct time. The use of wai to say thank you is widespread among Thais.
Generosity usually comes from the superior and the wai from the inferior.
Between equals, the wai can be used to say thank you but from a superior to an inferior it's out of place even if a significant service has been performed. The best advice to newcomers might be to stick to handshakes with men and a polite smile with women. Some Useful Hints 1. Do not wai servants, workers, children or other people of an obvious lower social status than yours. Ignoring this rule in some misguided attempt to create equality and to make friends will only result in embarrassment for the inferior.