e. g. natarā́m, kathaṁtarām, uccaistarā́m, çanāistarām, jyoktamā́m. In the oldest language (RV. and AV.), the neuter instead of the feminine form of these suffixes is almost alone in use: see 1119.
f. Many adverbs of obscure form or connection are to be explained with probability as accusatives of obsolete noun or adjective stems: examples are tūṣṇī́m in silence; sāyám at evening; sākám together, with (prep.); áram or álam sufficient (in the later language used with √kṛ in the manner of a prefix: 1078 a); prāyas usually; īṣát somewhat; amnás unexpectedly; bahís outside; míthu and mithás, múhu and múhus, jā́tu, and so on. Madrík etc., and niṇík (in RV.), are perhaps contracted forms of adjectives having √ac or añc as their final (407 ff.). The presence of other roots as final members is also probable for uçádhak, ānuṣák and āyuṣák, anuṣṭhú and suṣṭhú, yugapát, etc. Compare also the forms in am beside those in ā, above, 1101 a, 1102 e, 1103 b.
g. In (Vedic) dravát quickly is to be seen a change of accent for the adverbial use (pple drávant running); and drahyát stoutly (RV., once) may be another example. The comparative and superlative suffixes (above, e) show a like change; and it is also to be recognized in the derivatives with vát (1107).
1112. The instrumental is also often used with adverbial value: generally in the singular, but sometimes also in the plural. Thus:
a. Of pronominal stems: as, enā́ and ayā́, káyā, anā́, amā́, amuyā́.
b. Of noun-stems: as, kṣaṇena instantly; açeṣeṇa completely; viçeṣeṇa especially; dívā by day; diṣṭyā fortunately; sáhasā suddenly; aktubhis by night; and so on.
c. Of adjectives, both neuter (not distinguishable from masculine) and feminine: as, akhilena wholly; prāyeṇa mostly; dákṣiṇena to the south; úttareṇa to the north; ántareṇa within; ciréṇa long; — çánāis and çánakāis slowly; uccāís on high; nīcāis below; parācāís afar; táviṣībhis mightily; and so on.
d. More doubtful cases, mostly from the older language, may be instanced as follows: tiraçcátā, devátā, bāhúta, and sasvártā (all RV.), homonymous instrumentals from nouns in tā; dvitā́, tādī́tnā, īrmā́, mṛṣā́, vṛ́thā, sácā, asthā́ (?), mudhā (not V.), adhunā́ (B. and later).
e. Adverbially used instrumentals are (in the older language), oftener than any other case, distinguished from normal instrumentals by differences of form: thus, especially, by an irregular accent: as, amā́ and dívā (given above); perhaps gúhā; apākā́, āsayā́, kuhayā́ (?); naktayā́, svapnayā́, samanā́; adatrayā́, ṛtayā́, ubhayā́, sumnayā́ (?); daksinā́, madhyā́; nīcā́, prācā́, uccā́, paçcā́, tiraçcā́; vasántā; — in a few u-stems, by a y inserted before the ending, which is accented: thus, amuyā́ (given above), āçuyā́, sādhuyā́, raghuyā́, dhṛṣṇuyā́, anuṣ-