i. Before r, the cases are few, and the usage apparently divided: thus, takra, sakra, vakrá, çukrá, vigrá, ugrá, túgra, mṛgra, ván̄kri; but vájra and pajrá (?).
j. Before v (of the suffixes va, van, vin, etc., and participial vāṅs) the guttural is regularly preserved: thus, ṛkvá, pakvá, vákva; vákvan, ṛ́kvan, rikvan, çukvan, mṛgvan, túgvan, yugvan; ṛ́kvant, pṛ́kvant; vāgvín, vagvaná, vagvanú (with further sonant change); vivakvā́ṅs, ririkvā́ṅs, vivikvā́ṅs, rurukvā́ṅs, çuçukvā́ṅs; çuçukvaná, çuçukváni: also before the union-vowel i in okivā́ṅs (RV., once). An exception is yájvan.
k. The reversion of h in derivation is comparatively rare. The final j which is analogous with ç (219) shows much less proclivity to reversion than that which corresponds with c.
l. A like reversion shows itself also to some extent in conjugational stem-formation and inflection. Thus, the initial radical becomes guttural after the reduplication in the present or perfect or desiderative or intensive stems, or in derivatives, of the roots ci, cit, ji, hi, han, and in jáguri (√jṛ); and han becomes ghn on the elision of a (402, 637). The RV. has vivakmi from √vac and vāvakre from √vañc; and SV. has sasṛgmahe (RV. -sṛj-). And before ran etc. of 3d pl. mid. we have g for radical j in asṛgran, asṛgram, asasṛgram (all in RV.).
217. Final च् c of a root or stem, if followed in internal combination by any other sound than a vowel or semivowel or nasal, reverts (43) to its original guttural value, and shows everywhere the same form which a क् k would show in the same situation.
Thus, vákti, uváktha, vákṣi, vakṣyā́mi, vaghdi; vhāgbhís, vākṣú; uktá, ukthá, vaktár.
a. And, as final c becomes k (above 142), the same rule applies also to c in external combination: thus, vā́k ca, vā́g ápi, vā́n̄ me.
Examples of c remaining unchanged in inflection are: ucyáte, riricré, vācí, mumucmáhe.
217. Final श् ç reverts to its original क् k, in internal combination, only before the स् s of a verbal stem or ending (whence, by 180, क्ष् kṣ); before त् t and थ् th, it everywhere becomes ष् ṣ (whence, by 197, ष्ट् ṣṭ and ष्ठ् ṣṭh); before ध् dh, भ् bh, and सु su of the loc. pl., as when final (145), it regularly becomes the lingual mute (ट् ṭ or ड् ḍ).
Thus, ávikṣata, vekṣyā́mi; váṣṭi, viṣṭá, dídeṣḍu; didiḍḍhi, viḍbhís.