the full form of root in the strong persons of the singular active. Thus, from √vac speak come ūc and uvac; from √vas dwell come ūṣ and uvas; and so on.
a. The roots showing this abbreviation are vac, vap, vad, vaç, vas, vah; and vā weave is said to follow the same rule.
b. A single root beginning with ya, namely yaj offer, has the same contraction, forming the stems iyaj and īj.
c. Occasional exceptions are met with: as, vavāca and vavakṣé (RV.); vavāpa and vavāha and vavāhatus (E. and later); yejé (V.).
785. A number of roots having ya after a first initial consonant take i (from the y) instead of a in the reduplicating syllable: thus, from √vyac comes vivyac; from √pyā comes pipyā.
a. These roots are vyac, vyath, vyadh, vyā, jyā, pyā, syand; and, in the Veda, also tyaj, with cyu and dyu[errata 1], which have the root-vowel u. Other sporadic cases occur.
b. A single root with va is treated in the same way: namely svap, which forms suṣvap.
c. These roots are for the most part abbreviated in the weak forms: see below, 794.
786. A considerable number of roots have in the Veda a long vowel in their reduplication.
a. Thus, of roots reduplicating with ā: kan, kḷp, gṛdh, tṛp, tṛṣ, dṛh, dhṛ, dhṛṣ, nam, mah, mṛj, mṛç, ran, radh, rabh, vañc, van, vaç, vas clothe, vāç, vṛj, vṛt, vṛdh, vṛṣ, çad prevail, sah, skambh. Some of these occur only in isolated cases; many have also forms with short vowel. Most are Vedic only; but dādhāra is common also in the Brāhmaṇa language, and is even found later. As to jāgṛ, see 1020 a.
b. Of roots reduplicating with ī: the so-called roots (676) dīdhī and dīdī, which make the perfect from the same stem with the present: thus, dīdétha, dīdā́ya; dīdhima, dīdhyus (also dīdhiyus, dīdiyus). But pīpī has pipye, pipyus, etc., with short i. In AV. occurs once jīhīḍa, and in AB. (and AA.) bībhāya.
c. Of roots reduplicating with ū: tu, jū, and çū (or çvā).
787. A few roots beginning with the (derivative: 42) palatal mutes and aspiration show a reversion to the more original guttural in the radical syllable after the reduplication: thus, √ci forms ciki; √cit forms cikit; √ji forms jigi; √hi forms jighi; √han forms jaghan (and the same reversions appear in other reduplicated forms of these roots: 216 l). A root dā protect is said by the grammarians to form digi; but neither root nor perfect is quotable.
788. A small number of roots with initial a or ṛ (ar) show the anomalous reduplication ān in the perfect.
a. Thus (the forms occurring mainly in the older language only):
