715. In RV., this root is regularly inflected in the present-system according to the nu-class, making the stem-forms kṛṇó and kṛṇu; the only exceptions are kurmas once and kuru twice (all in the tenth book); in AV., the nu-forms are still more than six times as frequent as the u-forms (nearly half of which, moreover, are in prose passages); but in the Brāhmaṇa language and later, the u-forms are used to the exclusion of the others.
a. As 1st sing. pres. act. is found kurmi in the epos.
b. What irregular forms from kṛ as a verb of the nu-class occur in the older language have been already noticed above.
c. The isolated form taruté, from √tṛ, shows an apparent analogy with these u-forms from kṛ.
716. A few verbs belonging originally to these classes have been shifted, in part or altogether, to the a-class, their proper class-sign having been stereotyped as a part of the root.
a. Thus, in RV. we find forms both from the stem inu (√i or in), and also from ínva, representing a derivative quasi-root inv (and these latter alone occur in AV.). So likewise forms from a stem ṛṇva beside those from ṛṇu (√ṛ); and from hinva beside those from hinu (√hi). The so-called roots jinv and pinv are doubtless of the same origin, although no forms from the stem pinu are met with at any period — unless pinvire (above, 699 b) be so regarded; and AV. has the participle pinvánt, f. pinvatī́. The grammarians set up a root dhinv, but only forms from dhi (stem dhinu) appear to occur in the present-system (the aorist adhinvīt is found in PB.).
b. Occasional a-forms are met with also from other roots: thus, cinvata etc., dunvasva.
V. Nā-class (ninth or krī-class).
717. The class-sign of this class is in the strong forms the syllable ना nā́, accented, which is added to the root; in the weak forms, or where the accent falls upon the ending, it is नी nī; but before the initial vowel of an ending the ई ī of नी nī disappears altogether.
1. Present Indicative.
718. Example of inflection: root क्री krī buy: strong form of stem, क्रीणा krīṇā́; weak form, क्रीणी krīṇī (before a vowel, क्रीण् krīṇ).