449. The feminine participle-stem, as already stated, is made by adding ई ī to either the strong or the weak stem-form of the masc.-neut. The rules as to which of the two forms shall be taken are the same with those given above respecting the nom. etc. dual neuter; namely:
a. Participles from tense-stems ending in unaccented a add ī to the strong stem-form, or make their feminines in antī.
b. Such are the bhū or unaccented a-class and the dīv or ya-class of present-stems (chap. IX.), and the desideratives and causatives (chap. XIV.): thus, from √bhū (stem bháva), bhávantī; from √dīv (stem dī́vya), dī́vyantī; from búbhūṣa and bhāváya (desid. and caus. of √bhū), búbhūṣantī and bhāváyantī.
c. Exceptions to this rule are now and then met with, even from the earliest period. Thus, RV. has járatī, and AV. the desiderative síṣāsatī; in B. occur vadatī, çocatī, tṛpyatī, and in S. further tiṣṭhatī, and the causative namayatī; while in the epics and later such cases (including desideratives and causatives) are more numerous (about fifty are quotable), though still only sporadic.
d. Participles from tense-stems in accented á may add the feminine-sign either to the strong or to the weak stem-form, or may make their feminines in ántī or in atī́ (with accent as here noted).
e. Such are the present-stems of the tud or accented á-class (751 ff.), the s-futures (932 ff.), and the denominatives (1053 ff.): thus, from √tud (stem tudá), tudántī or tudatī́; from bhaviṣyá (fut. of √bhū), bhaviṣyántī or bhaviṣyatī́; from devayá (denom. of devá), devayántī or devayatī́.
f. The forms in ántī from this class are the prevailing ones. No future fem. participle in atī́ is quotable from the older language. From pres.-stems in á are found there ṛñjatī́ and siñcstī́ (RV.), tudatī́ and pinvatī (AV.) From denominatives, devayatī́ (RV.), durasyatī́ and çatrūyatī́ (AV.). In BhP. occurs dhakṣyatī.
g. Verbs of the ad or root-class (611 ff.) ending in ā are given by the grammarians the same option as regard the feminine of the present participle: thus, from √yā, yā́ntī or yātī́. The older language affords no example of the former, so far as noted.
h. From other tense-stems than those already specified — that is to say, from the remaining classes of present-stems and from the intensives — the feminine is formed in atī́ (or, if the stem be otherwise accented than on the final, in atī) only.
i. Thus, adatī́ from √ad; júhvatī from √hu; yuñjatī́ from √yuj; sunvatī́ from √su; kurvatī́ from √kṛ; krīṇatī́ from √krī; dédiçatī from dédiç (intens. of √diç).