1. In the better known South Dravidian languages, the verb system is such that two principal parts, or two stems, suffice as a basis on which the whole system may be built. The second stem is in general derivable from the first by the addition of a suffix *-i- or a suffix containing a dental stop (sometimes disguised by morphophonemic alternations), and is the basis for the past tense alone, or, in some of the languages, for present-future and past tenses, or for other combinations of forms. On the first stem are built all the remaining positive forms and the negative forms. Vocalic alternation within the stems, either of quality or of quantity, is very rare, but in the extremely few verbs where it occurs tends to be persistent throughout the history of all the languages; e.g. the verb ‘see’ has stems *ka·ṇ-, *kaṇṭ- in Tamil, Malayalam, Kannada, Coorg, and Toda, while Kota shows variation between ka#x0387;ṇ- and kaṇ- in the first stem, with leveling begun but not yet completed, or perhaps completed but with the disturbing long vowel reappearing by loan from other languages of the group. Likewise, any deviation from the suffixes given above as forming the second stem is rare.