Expressing the notion of `means by which an action was done' corresponds least to any one set of prepositions or other constructions in English, and also varies widely dialectally in Tamil. Basically the form of the instrumental case marker is È×Á -aale but some dialects use this only with pronouns:
Ç»ÆÔ×Á adan-aale `because of him '
Other dialects use Ñ×¹ -oode, the associative case marker, with inanimate nouns to express instrumentality:
ÀÕ¡øÔØÂÔ×¹ riksaavoode `by rikshaw'
Most dialects use the locative ×Á -le to express `by means of' with modes of transportation:
½öÓ×Á basle `by bus '
In some dialects no genuine instrumental case marker is found, and postpositions such as ñÁ£ muulam `by means of' or Ð»ÂÕ odavi `help' are used instead. Sometimes both are used:
×¹¤Ü ×À÷ÕöÓ¥ÀÔ¯ Ð»ÂÕ ñÁ£
depti rejistraar otavi muulam
`under the auspices of (with the help of) the deputy registrar'
In still other cases, verbal constructions substitute for a true instrumental case construction:
Ø¶Ô¤ Íà¢â ×»Ô×Â¡´ÁÔ£ soop eduttu tovekkalaam
`(one) may wash (it) with soap' (`taking soap, one may wash ').
Research on causatives and instrumental constructions in various languages has shown this semantic area to be rather complex, so definitive statements about Tamil constructions of this sort must remain highly tentative.
(Cf. section 2.3 on postpositions for the equivalence of other English prepositions.) Note that -aale alternates with the dative with the modal verb åÜæ£ mudiyum `be able':
As we shall see later, there is often a difference of meaning: the instrumental implies that a person is not only physically able but also willing to make an effort, whereas the dative implies only physical capability, not necessarily willingness.