Tane & tidder

Shaetlan has the pronoun opposition da tane ... da tidder which translates to St English 'the one ... the other'. This is found in various forms in the entire Scots speaking area, and is neither new, nor "slang", nor "improper". These are old forms, which emerged in late Old English, especially in the northern areas, around 1200-1250: þe became the general form for the definite article ('the') and so the -t in þæt ān 'the/that one' got shifted to ān so that it became þæ tān > þe tane > da tane 'the one' instead. The same happened with þæt ōðer 'the/that other' which became þæ tōðer > þe tithyr > da tidder 'the other'. Apart from the Scots speaking areas, it is only found in various forms in pockets of convervative English varieties, but no longer in Standard English.