This important period of studies was concerned with the preservation and interpretation of the Vedic texts. This is visible in the preparation of the Padapatha of the Rig Veda by Sakalya. The grammarians were concerned with the spoken speech of the day and from this grew more distinct language from the sacred texts on the one hand and the speeches of the lower classes on the other. Panini cites by name many predecessors that also include Jakatayana, Apicali, and Qaunaka. Panini summarizes the efforts of many previous writers.
The Ashtadayai of Panini consists of about 4,000 short Sutras that are divided into eight books. It treats technical terms and rules of interpretation, nouns in composition and case relations; the adding of suffixes to roots and to nouns, accent and changes of sound in word formation and the word in the sentence. Grammar's main objective is to deal with the living speech of the day. The major principle underlying the grammar is the derivation of nouns from verbs. All derivation is done by affixes thereby making it necessary to assume suffixes which are invisible. In Phonetics Panini and his predecessors achieved remarkable results. The analysis of forms is carried out with great acumen.
In order to secure brevity that are aimed at many devices; the case are used, verbs are omitted, leading rules are understood and algebraic formulae replace real words. The rule that a vowel is changed into the corresponding semi-vowel is also applied. There are some technical terms that are older than Panini.
Katyayana most probably lived in the third century B.C. It is seen that he is attacking or correcting Panini on the grounds of differences in usage which arose between the times of the two. He examine criticisms, rejecting some, accepting others thus enhancing and limiting Panini's rules. Patanjali had many criticisms and works before him beside that of Katyayana. The variety of metres used in these verses is remarkable. It also includes some later quite rare and complex, metres.
Patanjali is believed to be the author of the Yoga Sutra. The Mahabhasya is interesting as it gives a lively picture of the mode of discussion of that time. The style is lively, simple and animated. Proverbial expressions and reference to matters of everyday life are also introduced. It serves both to liven up the discussions as well as to give valuable hints of the conditions of life and thought in the time of Patanjali.
Patanjali closes the line of great grammarians. He drew on the speech of his day. He insists on the absurdity of learning words that are not used. He considers Panini in the light of a living language. The authority of Panini and his immediate followers prevailed.
Pingala is the traditional name of the author of the Chandansastra. It is the earliest known Sanskrit treatise on inflection. Shaunaka is a Sanskrit grammarian, author of the Rigveda-Pratisakhya, the Brhaddevata, the Carana-vyuha and five indices to the Rig Veda. It is claimed that he was the teacher of Katyayana. Virahanka was an Indian prosodist. He is also known for his work on mathematics. He possibly lived in the 6th century. He preceded Panini. He is the author of the Nirukta which is a technical treatise on etymology. Sakatayana is a Sanskrit grammarian. It is roughly estimated that he flourished in the 8th century. His work was referred by scholars such as Yaska and Panini.
Panini could not teach Sanskrit. Therefore re-writing and re-arrangement were essential, that lead to Ramachandra's Prakriya kaumudi based on which is Bhattoji Diksita's well-known and Siddhantakaumudi. On this he wrote a comment, the Praudhamanorama. From this came two school grammars of Varadaraja, Madhyasiddhantakanmudi and Laghukaumudi.