The root in general remains unchanged; but with the following exceptions:

a. A final i or u is lengthened before sa: thus, cikṣīṣa, cikīṣa, jigīṣa; çuçrūṣa, juhūṣa, cukṣūṣa.

c. Before iṣa, a final i- or u- or ṛ-vowel necessarily, and a penultimate i or u or ṛ optionally, have the guṇa-strengthening; no examples are quotable from the older texts; later occurçiçayiṣa, çiçariṣa; cikartiṣa, ninartiṣa, mimardiṣa, vivarṣiṣa, çuçobhiṣa; but rurudiṣa.

More special exceptions are:

d. A few roots in ā weaken this vowel to ī or even i: thus, jigīṣa from √gā go; pipīṣa (beside pipāsa) from √pā drink, jihīṣa (AV.) from √hā remove (jihīte: 664); didhiṣa(beside dhitsa) from √dhā.

e. A few roots in an or am lengthen the vowel: thus, jigāṅsa (beside jigamiṣa) from √gam; jighāṅsa from √han; mīmāṅsa from √man; and titāṅsa from √tan.

f. Reversion to guttural form of an initial after the reduplication is seen in cikīṣa from √ci, cikitsa from √cit, jigīṣa from √ji, jighāṅsa from √han; and √hi is said to makejighīṣa (no occurrence).

g. The roots van and san make vivāsa and siṣāsa, from the root-forms vā and sā.

h. The root jīv forms jujyūṣa (ÇB.: jijīviṣa, VS.); and the other roots in īv (765) are required to make the same change before sa, and to have guṇa before iṣa: thus, susyūṣa orsiseviṣa from √sīv. Svap forms suṣupsa. Dhūrv forms dudhūrṣa.

i. Initial s is usually left unchanged to ṣ after the reduplication when the desiderative sign has ṣ (184e): thus, sisan̄kṣa (ÇB.: √sañj), and susyūṣa and sisaniṣa, according to the grammarians; but tuṣṭūṣa is met with.

j. Further may be mentioned as prescribed by the grammarians: ninan̄kṣa (or ninaçiṣa) from √nāç be lost; miman̄kṣa from √majj (occurs in miman̄kṣu); mimārjiṣa (or mimṛkṣa) from √mṛj.