b. The Vedas show no other irregularities of inflection than those which belong to all stems in a and ā: namely, ténā sometimes; usually tā́ for tāú, du.; often tā́ for tā́ni, pl. neut.; usually tébhis for tāís, instr. pl.; and the ordinary resolutions. The RV. has one more case-form from the root sa, namely sásmin (occurring nearly half as often as tásmin); and ChU. has once sasmāt.
496. The peculiarities of the general pronominal declension, it will be noticed, are these:
a. In the singular, the use of t (properly d) as ending of nom.-acc. neut.; the combination of another element sma with the root in masc. and neut. dat., abl., and loc., and of sy in fem. dat, abl.-gen., and loc.; and the masc. and neut. loc. ending in, which is restricted to this declension (except in the anomalous yādṛ́çmin, RV., once). The substitution in B. of āi for ās as fem. ending (307 h) was illustrated at 365 d.
b. The dual is precisely that of noun-stems in a and ā.
c. In the plural, the irregularities are limited to té for tā́s in nom. masc., and the insertion of s instead of n before ām of the gen., the stem-final being treated before it in the same manner as before su of the loc.
497. The stem of this pronoun is by the grammarians given as tad; and from that form come, in fact, the derivative adjective tadī́ya, with tattvá, tadvat, tanmaya; and numerous compounds, such as tacchīla, tajjña, tatkara, tadanantara, tanmātra, etc. These compounds are not rare even in the Veda: so tádanna, tadvíd, tadvaçá, etc. But derivatives from the true root ta are also many: especially adverbs, as tátas, tátra, táthā, tadā́; the adjectives tā́vant and táti; and the compound tādṛ́ç etc.
498. Though the demonstrative root ta is prevailingly of the third person, it is also freely used, both in the earlier language and in the later, as qualifying the pronouns of the first and second person, giving emphasis to them: thus, sò ‘hám, this I, or I here; sá or sā́ tvám thou there; te vayam, we here; tasya mama of me here, tasmiṅs tvayi in thee there, and so on.
499. Two other demonstrative stems appear to contain ta as an element; and both, like the simple ta, substitute sa in the nom. sing. masc. and fem.