The English so-called modal auxiliaries `may, can, must, might, should, ought, could', etc., have their Tamil equivalents in auxiliary verbs that are attached to the infinitive of the verb. If that verb happens to be aspectually marked (cf. § 3.6) the modal is attached to the infinitive of the aspect marker. The negative forms of the modals differ from the positive forms, often strikingly, but behave syntactically the same. The Tamil modal verbs are invariant for PNG, but some exhibit a basic distinction between habitual and non-habitual action, and some can be distinguished for tense, especially in the negative. Pragmatic considerations enter in, because the speech act may result in the giving (or denying) permission, or prohibition of certain actions.
This table oversimplifies things to a great extent, because negation with modality tends to be skewed, i.e. the SCOPE of the negation can vary: one can be negating the need to do something, or emphasizing the need not to do something. This results in different negative forms for the one positive modal verb. Modals often involve a semantic component of HABITUALITY so there can be a contrast between simple one-time negation, and habitual negation.
As we have already seen (§ xxx) Tamil tends to omit pronouns when it is clear to speaker and hearer who the actors are. If these forms are negated, there are other pragmatic considerations. For example, ǥ࣠attum is normally used with third-persons in mind, e.g. Ǩ ÂÀ¥à£ avan varattum `let him come', É紥࣠irukkattum `let it be' in declarative sentences. But in interrogatives, the implicature is that the speaker is asking to be given permission, not asking whether someone else has permission:
Here are more examples of the complexities of the use of modals:
Note that since modals are never marked for PNG, the same forms are used regardless of the person-number-gender of the subject.
Note also that the modal ØÂᣠveenum has the form ᣠnum after a verb, but the full form ØÂᣠveenum when it stands alone. This deletion of Ø vee- does not occur with ØÂý¹Ô£ veendaam.