को: SocialRel ~> Recipient

Nouns such as "children" (which seems to be a fossilized expression from back when there were several competing postpositions for social relations) will have SocialRel↝Recipient. One interpretation is that the parents "receive" children, and that is why other social relations aren't included in this postposition. However, Old Hindi/Urdu seems not have had this restriction so it's iffy.

• दम्पति
  couple

  को
  DAT

  कोई
  any

  संतान
  offspring

  नहीं
  not

  थी
  be-PST

  ।

  'The couple did not have any children.' 001