When being introduced or greeting someone, men say Sawatdee-krap and women say Sawatdee-kah.
Thais greet each other with a “wai.” Foreigners are not expected to initiate the wai gesture, but it is an insult not to return the wai. If a wai is not offered to you, shake hands with men and smile and nod to women. A Thai businessperson may shake hands with a foreigner. Offer a wai only to a person of equal or greater status. Subordinates should offer a wai first.
Wai (why) – a person places the palm of his or her hands together, with their fingers extended at chest level close to their body and bows slightly. The higher the hands are placed, the more respect is shown. Subordinates might raise their fingers as high as their nose. However, the tips of their fingers should never be above eye level.