Thai, or Siamese, is the sole official and national language of Thailand, and the first language of the Central Thai people and vast majority of Thai of Chinese origin. Over half of Thai vocabulary is derived from or borrowed from Pali, Sanskrit, Mon, and Old Khmer. It is a tonal and analytic language, with a complex orthography and system of relational markers.
Native speakers: 20 to 36 million people.
All the World Languages in One Visualization: A World of Languages.