Kalithogai is an anthology of 150 poems in kali metre of varied length dealing with all phases and types of love experience. The poems are categorised into the five thinais according to the mood and subject matter conforming to the Sangam landscape. The first part (2-36) deals with paalai setting, the second (37-65) with kurinchi, the third (66-100) with marutam, the fourth (101-117) with mullai and the fifth (118-150) with neital. These five section were each written by a separate author. Perunkadunkon wrote the paalai songs, the poet Kapilar is attributed to the kurinchi, Ilanaagan the marutham songs, Nalluruthiran the mullai songs and the poet nallanthuvan the neithal songs. However, modern scholarship attributes the entire work to a single author.
Considering the style and usage of words, the work is also considered to be of a later period when compared to most of other Sangam works. The name of the compiler of Kalithogai and his patron are not known. The book of annotations for this book written by Nachinarkiniyaar in the mid fifteenth century says that Nallanthuvanaar compiled the Kalithogai anthology.
The poems of Kalithogai show evidence of the ancient music of the Tamil people with its rhythmic phrases.
One of the best examples from this compilation is the one attributed to Nallanthuvanar.
ஆற்றுதல்' என்பது, ஒன்று அலந்தவர்க்கு உதவுதல்;
போற்றுதல்' என்பது, புணர்ந்தாரை பிரியாமை;
பண்பு' எனப்படுவது, பாடு அறிந்து ஒழுகுதல்;
அன்பு' எனப்படுவது, தன் கிளை செறாஅமை;
அறிவு' எனப்படுவது, பேதையார் சொல் நோன்றல்;
செறிவு' எனப்படுவது, கூறியது மறாஅமை;
நிறை' எனப்படுவது, மறை பிறர் அறியாமை;
முறை' எனப்படுவது, கண்ணோடாது உயிர் வௌவல்;
பொறை' எனப்படுவது, போற்றாரை பொறுத்தல்.
Goodness is helping one in distress;
Support is not deserting one who is dependent;
Culture is to act in unison with the ways of the world;
Love is not surrendering ties with one’s kin;
Wisdom is to ignore the advice of the ignorant;
Honesty is not to go back on one’s words;
Integrity is to ignore others’ faults;
Justice is awarding punishment without partiality;
Patience is to suffer the ill-disposed.