root is hardly perceptibly modified by the addition of the prefix. An intensive force is not infrequently given by pari, vi, and sam.
1078. Prefixes essentially akin with the above, but more distinctly adverbial, and of more restricted use, are these:
ácha (or áchā) to, unto: tolerably frequent in RV. (used with over twenty roots), but already unusual in AV. (only two roots), quite restricted in B., and entirely lost in the later language;
āvís forth to sight, in view: used only with the roots bhū, as, and kṛ;
tirás through, crossways; out of sight: hardly used except with kṛ, dhā, bhū (in RV., with three or four others);
purás in front, forward: used with only half-a-dozen roots, especially kṛ, dhā, i;
prādús forth to view: only with bhū, as, kṛ.
a. A few others, as bahis outside, vinā without, alam (with bhū and kṛ) sufficiently, properly, sākṣāt in view, are still less removed from ordinary adverbs.
1079. Of yet more limited use, and of noun-rather than adverb-value, are:
çrad (or çrath?), only with dhā (in RV., once also with kṛ): çraddhā believe, credit;
hin̄, only with kṛ (and obsolete in the classical language): hin̄kṛ make the sound, hing[errata 1] low, murmur.
a. And beside these stand yet more fortuitous combinations: see below, 1091.
1080. More than one prefix may be set before the same root. Combinations of two are quite usual; of three, much less common; of more than three, rare. Their order is in general determined only by the requirements of the meaning, each added prefix bringing a further modification to the combination before which it is set. But आ ā́ is almost never allowed, either earlier or later, to be put in front of any of the others.
a. The very rare cases of apparent prefixion of ā to another prefix (as āvihanti MBh., āvitanvānāḥ BhP.) are perhaps best explained as having the ā used independently, as an adverb.
1081. In classical Sanskrit, the prefix stands immediately before the verbal form.
a. In the earlier language, however (especially in the Veda; in the Brāhmaṇa less often and more restrictedly), its position is quite
