The rai (, ) is probably the oldest Thai poetic form and was used in laws and chronicles. It is also the simplest. It consists of a continuing series of wak of unspecified number, usually with five syllables each, and with rhymes from the last syllable of a wak to the first, second or third of the next. Some variations don't specify the number of syllables per wak and are actually a form of rhymed prose. A composition consisting of rai alternating with (and ending with) khlong is known as lilit (, ), and suggests that the khlong developed from the rai. The following is the form of rai known as rai boran (, ). Reproduced form
