Notes :Irregular (expressive?) vowel lengthening is observed in some Gondwan languages. This is one of the two main PDR roots for 'father', the other being *t-and_-; judging by the difference in meaning, the latter was the more 'formal' appellation (which is why it is more frequently met with archaic pronominal prefixes than *ápa-), whereas the latter is clearly a "children's" word. // Present in 4/6 branches.