THE VERB 303 conjugation, namely causatives with stems in - aya t desidera- tives with reduplicated stems in sa , intensives with strong re- duplication and radical stem or stem in ya. These were origin- ally conjugated in the present system only and it is a special development of Sanskrit which allows them to be inflected in other parts of the verbal system. With these must be classified the passive which is a special development of the fourth class and which arises from a tendency of stems of that class to specialise as intransitives. §4. Accent and Apophony of Verbal Stems By a rule peculiar to Sanskrit, the like of which is not trace- able in other IE languages, the verb is unaccented in an inde- pendent clause, except at the beginning of such a clause and under certain special conditions ; it retains its accent in de- pendent clauses. When accented the verbal stem has an un- changeable accent in the case of thematic formations, which in this respect agree entirely with the nominal thematic formations. In the non-thematic formations the accent varies between stem and personal ending, and this variation corresponds to a varia- tion between the guna (occasionally vrddhi) grade of the stem and the zero grade. The general rule is that in the indicative the stem has the accent and the guna grade in the three persons of the singular active, and that in the dual and plural of the active and in the whole of the middle the accent is on the termin- ation and the stem appears in its weak form : dvisti f hates ', 3 pi, dvisanti , 3 sg, mid. dvistd, yundkti ' joins 3 pL yunjdnti, 3 sg. mid. yunktd . 'Exceptions to the rule (e.g, in the s-aorist) are comparatively rare. This old IE system appears also in other languages (e.g. Gk. etfju t/xev), though nowhere so clearly and consistently as in Sanskrit. §5. Augment and Reduplication In addition to a large variety of suffixation Indo-European made use of two types of prefixation in the formation of tense stems, Augment and Reduplication. The augment (IE e-, Skt, a -) is prefixed to the various pre- terites (imperfect, aorist, pluperfect, conditional) to indicate past time. It is found in Indo-Iranian (Skt. abharai ), Greek (e<£ep€), Armenian (eber), and Phrygian (eSa*? 'constructed'), but it is absent in the rest of Jndo-European. It is thus an
