Subrahmanya Sastri did his S.S.L.C. at National High School, F.A. at St. Joseph's College and B.A. Mathematics at SPG (later Bishop Heber's) College – all in Tiruchirappalli. He started his professional career as a Mathematics assistant at the Central High School (now Srinivasa Rao Higher Secondary School), Thiruvaiyaru, and National High School, Tiruchi.
He studied Sanskrit under Nilakanta Sastri, a specialist in grammar and philosophy. He also learnt Nyaya (logic) and Alankara Sastra (Poetics and Literary Criticism) from Prof. S. Kuppuswami Sastri of the Madras Presidency College (professor of Sanskrit and comparative philology, and curator of the Government Oriental Manuscripts Library, Madras) and Mimamsa (Linguistics) from Chinnaswami Sastri of the Benares Hindu University. A graduate in M.A. (Sanskrit), Subrahmanya Sastri also passed L.T. through Teachers’ Training College at Saidapet, Chennai.
While teaching Sanskrit, Subrahmanya Sastri had to teach Tamil also. This paved the way for his in-depth study in both Sanskrit and Tamil, specifically grammar. Prof. Kuppuswami Sastri also taught him the Comparative Philology of Indo Aryan languages. All these inspired Subrahmanya Sastri to take up a systematic study of Tamil literature and grammar.