Other than compound words and words of foreign origin, most words are monosyllabic. Historically, words have most often been borrowed from Sanskrit and Pāli; Buddhist terminology is particularly indebted to these. Old Khmer has also contributed its share, especially in regard to royal court terminology. Since the beginning of the 20th century, however, the English language has had the greatest influence, especially for scientific and technical vocabulary. Many Teochew Chinese words are also used, some replacing existing Thai words (for example, the names of basic numbers; see also Sino-Xenic).
As noted above, Thai has several registers, each having certain usages, such as colloquial, formal, literary, and poetic. Thus, the word “eat” can be กิน (kin; common), แดก (daek; vulgar), ยัด (yat; vulgar), บริโภค (boriphok; formal), รับประทาน (rapprathan; formal), ฉัน (chan; religious), or เสวย (sawoei; royal).
Thailand also uses the distinctive Thai six hour clock in addition to the 24 hour clock.