a. Medial or initial i, u, ṛ, ḷ have the guṇa-strengthening (if capable of it: 240; thus, vedaya from √vid, codaya from √cud, tarpaya from √tṛp; and kalpaya from √kḷp (only example): but cintaya, gulphaya, dṛṅhaya.

b. But a few roots lack the strengthening: these are, in the older language, cit (citaya and cetaya), iṣ, iḷ, riṣ (riṣaya and reṣaya), vip (vipaya and vepaya), tuj, tur, tuṣ (tuṣaya and toṣaya), dyut (dyutaya and dyotaya), ruc (rucaya and rocaya), çuc (çucaya and çocaya), çubh (cubhaya and çobhaya), kṛp, mṛḍ, spṛh; and grabhmakes in RV. gṛbhaya. Duṣ and guh lengthen the vowel instead. Mṛj sometimes has vṛddhi, as in other forms: thus, mārjaya (beside marjaya). On the other hand, guṇa appears irregularly (240 b) in srevaya (beside çrīvaya), heḍaya, mekṣaya. Similar irregularities in the later language are giraya, tulaya (also tolaya), churaya (also choraya),muṣaya, sphuraya. No forms without strengthening have a causative value made in the older language.

c. A final vowel has the vṛddhi-strengthening: thus, cāyaya, çāyaya, cyāvaya, bhāvaya, dhāraya, sāraya.

d. But no root in i or ī has vṛddhi in the Veda (unless pāyaya [k, below] comes from pī rather than pā) — as, indeed, regular causatives from such roots are hardly quotable: only RV. has kṣayaya (beside kṣepaya) from √kṣi possess; for a few alternatively permitted forms, see below, 1. In B. and S., however, occur çāyaya and sāyaya (√si or sā); and later -āyaya, cāyaya, smāyaya, ḍāyaya, nāyaya.

e. A few roots have a form also with guṇa-strengthening: thus, cyu, dru, plu, yu separate, çru, pū, stu, sru; jṛ waste away, dṛ pierce, sṛ, smṛ, hṛ; vṛ choose makesvaraya later (it is not found in V.: epic also vāraya).

f. A medial or initial a in a light syllable is sometimes lengthened, and sometimes remains unchanged: thus, bhājaya, svāpaya, ādaya; janaya, çrathaya, anaya (butmandaya, valgaya, bhakṣaya).

g. The roots in the older language which keep their short a are jan, pan, svan, dhan, ran, stan, gam (gāmaya once in RV.), tam, dam, raj (usually rañjaya), prath, çrath, çnath, vyath, svad, chad please (also chandaya), nad, dhvas (also dhvaṅsaya), rah, mah (also maṅhaya), nabh (also nambhaya), tvar, svar, hval. In the later language, further, kvaṇ, jvar, trap, day, paṇ, rac, ran ring, vadh, val, vaç, çlath, skhal, sthag. Both forms are made (either in the earlier or in the later language, or in both taken together) by ad, kal, kram, kṣam, khan, ghaṭ, cam, cal, jval, tvar, dal, dhvan, nad, nam, pat, bhram, math, mad, yam, ram, lag, lal, vam, vyadh, çam be quiet, çram, çvas, svap. The roots which lengthen the vowel are decidedly the more numerous.

h. If a nasal is taken in any of the strong forms of a root, it usually appears in the causative stem: e. g. dambhaya, daṅçaya, indhaya, limpaya, rundhaya, çundhaya, kṛntaya, dṛṅhaya. From a number of roots, stems both with and without the nasal are made: thus (besides those mentioned above, g), kuñcaya and kocaya, granthaya andgrathaya, bṛṅhaya and barhaya, bhraṅçaya and bhrāçaya, çundhaya and çodhaya, sañjaya and sajjaya, siñcaya and secaya. In a few of these is seen the influence of present-stems.

i. Most roots in final ā, and the root ṛ, add p before the conjugation-sign: thus, dāpaya, dhāpaya, sthāpaya; arpaya.

j. Such stems are made in the older language from the roots kṣā, khyā, gā sing (also gāyaya), glā, ghrā, jñā, dā give, dā divide, drā run, dhā put and dhā suck, mā measure,mlā, yā, vā blow, sthā, snā, hā remove; the later language adds kṣmā, dhmā, and hā leave. From jñā and snā are found in AV. and later the shortened forms jñapaya andsnapaya, and from çrā only çrapaya (not in RV.). Also, in the later language, glā forms glapaya, and mlā forms mlapaya.

k. Stems from ā-roots showing no p are, earlier, gāyaya (also gāpaya) from √gā sing, chāyaya, pāyaya from √pā drink (or pī), pyāyaya from √pyā or pyāy; sāyaya from √sā (orsi); also, later, hvāyaya from √hvā (or hū); — and further, from roots vā weave, vyā, and çā (or çi), according to the grammarians.

l. The same p is taken also by a few i- and ī-roots, with other accompanying irregularities: thus, in the older language, kṣepaya (RV., beside kṣayaya) from √kṣi possess; jāpaya (VS. and later) from √ji; lāpaya (TB. and later; later also lāyaya) from √lī cling; çrāpaya (VS., once) from √çri; adhyāpaya (S. and later) from adhi+√i; — in the later, kṣapaya(beside kṣayaya) from √kṣi destroy; māpaya from √mī; smāpaya (beside smāyaya) from √smi; hrepaya from √hrī; — and the grammarians make further krāpaya from √krī;cāpaya (beside cāyaya) from √ci gather; bhāpaya (beside bhāyaya and bhīṣaya) from √bhī; repaya from √rī, and vlepaya from √vlī. Moreover, √ruh makes ropaya (B. and later) beside rohaya (V. and later), and √knū makes knopáya (late).

m. More anomalous cases, in which the so-called causative is palpably the denominative of a derived noun, are: pālaya from √pā protect; prīṇaya from √prī; līnaya (according to grammarians) from √lī; dhūnaya (not causative in sense) from √dhū; bhīṣaya from √bhī; ghātaya from √han; sphāvaya from √sphā or sphāy.

n. In the Prakrit, the causative stem is made from all roots by the addition of (the equivalent of) āpaya; and a number (about a dozen) of like formations are quotable from Sanskrit texts, mostly of the latest period; but three, krīḍāpaya, jīvāpaya, and dīkṣāpaya, occur in the epics; and two, açāpaya and kṣālāpaya, even in the Sutras.