The poems of Innilai deal with the ethical concepts of aram – propriety, porul – wealth, inpam – love and veedu – salvation.
Kainnilai is available in a much-damaged condition with many of its poems only partially available.
Agam in the Sangam literature denotes the subject matters that deal with the intangibles of life such as human emotions, love, separation, lovers' quarrels, etc.
The poems of Kainnilai are categoriesed into twelve poems for each of the five thinai, or landscape of Sangam poetry and describe in detail the situation and emotions specific to each landscape.
The five landscapes of Sangam poetry are mullai – forest, kurinji – mountains, marutham – farmland, paalai – arid land and neithal – seashore.