145. Of the sibilants

Of the sibilants, none may stand unaltered at the end of a word. The स् s (which of all final consonants would otherwise be the commonest) is, like र् r, changed to a breathing, the visarga. The श् ç either reverts (43) to its original क् k, or, in some roots, is changed to ट् ṭ (in accordance with its changes in inflection and derivation: see below, 218): thus, दिक् dik, but विट् viṭ. The ष् ṣ is likewise changed to ट् ṭ: thus, प्रावृट् prāvṛṭ.

a. The change of ṣ to ṭ is of rare occurrence: see below, 226 d.

b. Final radical s is said by the grammarians to be changed to t; but no sure example of this conversion is quotable; see 168; and compare 555 a.