This classificatory scheme does not work perfectly for ST, however, so we have proposed additional subclassifications for certain of Graul's classes, notably verbs in classes 2 (II) and 6 (VI), where stem-final front vowels trigger palatalization of the past tense markers nt and tt to [nj] and [cc], respectively. Verbs of classes 2 and 6 whose stems do not meet these conditions are not specially marked, but those that do are marked 2b and 6b, respectively. Thus the verb teri , 2 intr., with stem-final i triggering palatalization of the past marker nt to [nj] in spoken is classified as 2b, and camai , 6 tr., which has a palatalized past tense marker [cc] in ST, is classified as 6b.
In addition, in classes 2, 3, and 5 there are a number of irregular verbs that do not follow the regular rules in one or another tense form, so we have marked certain verbs as members of subclass 2c, or 3b, or 5c, to try to fit them into the class they most closely resemble. Most irregularities or complexities of the Tamil verb are to be found in the past tense; were it not for these past tense problems, most Tamil verbs could be classified simply as ``strong" or ``weak", depending on whether they have doubled consonants in the present ( kki6- ) and future ( pp ) tense marker, or single consonants ( ki6 ) and ( v / p ). This strong-weak scheme is used by some scholars and in some pedagogical materials for Tamil as a general description of the verb, but it is not adequate to predict the details of the past tense. It is useful if the discussion centers on the formation of infinitives or of neuter futures, and the strong-weak distinction also correlates in some ways with transitivity and intransitivity. But this correlation is not perfectly regular and can only serve as a mnemonic device when the exact classification cannot be remembered.
In ST, subclassifying classes 2, 3, 5, and 6 into palatalizing, non-palatalizing, and otherwise irregular helps to take care of most areas where ST forms are different from Literary Tamil, but it does not take care of all. In some cases, ST verbs are members of totally distinct classes from their Literary Tamil counterparts, and this is particularly true of members of Literary Tamil classes 1 and 5---Literary Tamil class 1 is a very small class, i.e. has very few members, and given that some of these Literary Tamil verbs are never used in ST, while other members shift to another class, class 1 as a spoken class is an almost empty set. There are, however, a few members that retain and duplicate the morphology of the Literary Tamil set, so it must be retained. The Literary Tamil verb cey , 1 tr. `do, make' changes to class 2 in ST: its past is [senj-] rather than the Literary Tamil ceyt- [seyd-] (the verb pey `rain' also shifts to 2 in ST). But verbs like a7u `weep' and u7u `plow' remain in class 1 in spoken, with pasts in [d] analogous to Literary Tamil single t pasts: a7utee2 = [audeen] `I wept.'
Another Literary Tamil class that has lost members in ST is class 5---this is a class with final sonorants, and many irregular and unpredictible things happen to these stems in both Literary Tamil and in ST. In ST some of these are not used, or are used only with an aspectual auxiliary. For example kal `learn', with Literary Tamil past ka66- usually occurs in ST only with aspectual iru , e.g. [katt-iru], as in [tami engee kattirukkiinga?] `Where did you learn Tamil?' Other Literary Tamil class 5 verbs are not used at all, or only in certain idioms. The verb kaa3 `see' is not common in ST as a main verb, only in certain collocations or idioms such as [kanaa kaanu] `have (i.e. see) a dream', or in the archaic frozen negative form [kaanoom] `(I) don't see (a thing, etc.)'. Other class 5 verbs are shifted to class 3, e.g. ti2 `eat' which has the Literary Tamil past ti26een `I ate' is realized as [tinnineen] (with usual shortening of the cluster [nnin] to [nn]) and the Literary Tamil future ti2pee2 would be [tinnuveen]. But not all speakers do this, and some retention of this class, even at a minimal level, must be recognized. For example, the quotative verb e2 , phonologically reduced as it is, is in standard ST more or less a predictibly class 5 verb, with past in [nn-], present [ngr-] and future [mb-], although the future may also occur as [nnuv-], e.g. [appadi-ngraan] `that's what he says' or [appadi-mbaan] `that's what he'll say'. The pervasive use of this verb as a quotative marker and embedding marker in Tamil guarantees that it will appear very often in conversation and spoken texts, so despite the fact that e2 may be almost the only verb that retains features of class 5 morphology, its functional load is high in the language.