345. Roots ending in i or u

Roots ending in i or u (or : 376 b) regularly add a t when used as root-words or as root-finals of compounds; and hence there are no adjectives of the root-class in this declension.

a. Yet, in the Veda, a few words ending in a short radical u are declined as if this were suffixal: thus, ásmṛtadhru, suṣṭú; and the AV. has pṛtanājí (once). Roots in ū sometimes also shorten ū to u: thus, prabhú, vibhú, etc. (354); go (361 e) becomes gu in composition; and re perhaps becomes ri (361 e); while roots in ā sometimes apparently weaken ā to i (in -dhi from √dhā etc.: 1155).