Kongu Tamil is the most conservative of the major spoken Tamil registers, keeping verb endings and pronoun forms the coastal and delta varieties have simplified away, and holding a vocabulary of dry farming, cattle and clan that has no equivalent elsewhere. Its most quoted feature is semantic rather than phonetic: kaadu, which everywhere else in Tamil means forest, here means cultivated dry land — a farmer says he is going to the kaadu when he means his own field. On the slope and across the gap the language changes entirely within a few hours' travel.
Kongu TamilDravidian, Southern
The region's own register, with retained older morphology, distinctive kinship terms and a set of agrarian words a Chennai speaker will not recognise. It is well represented in Tamil cinema as a marked rural register, which its speakers regard with mixed feelings.
Palakkad Tamil and the gap bilingualismDravidian
Through the gap the households are Malayalam-speaking within a day's walk, but a long-settled Tamil-speaking population lives on the far side and a Malayalam-speaking one on this side. Trade, marriage and temple ties run both ways and always have.
BadagaDravidian
A separate language of the plateau above the slope, closely related to Kannada rather than to Tamil. It belongs to the hill world at the top of the escarpment, not to the plain, and is listed here because the slope is where the two meet in the market towns.
बोलने वाले: Some hundreds of thousands on the Nilgiri plateau
Irula and KurumbaDravidian
Languages of forest-dwelling communities on the Nilgiri and Sathyamangalam slopes, each with a detailed vocabulary for honey, forest seasons and plants.
Kannada and Telugu of the north-eastern edgeDravidian
Household languages in the Dharmapuri and Krishnagiri belt and in pockets of the Salem hills, reflecting settlement across the Cauvery long before any modern boundary.