Four words and two sentences
Each line of poetry has four words, forming two sound groups (or steps). The sentence structure is "2─2". Most of the poems in the Book of Songs belong to this form.
Two words have one meal, and each line of poetry has two meal. Since there are many monosyllabic words in ancient Chinese, in order to make the rhythm of two words and one sentence regular, words are overlapped on the monosyllabic words, or particles are added behind the monosyllabic words.