How about "THAT man is my uncle"? I know there's this word tamten as well, so say you're pointing at a man across the room, would you use ten or tamten?
50/50. I think when it isn't about contrasting ('Ten pan to mój brat, a tamten to mój wujek') it is up to personal preference.
I would say that is OK really in a spoken Polish. According to the dictionary this is usually 'ten' while that is 'tamten' and in both Polish and English they are used interchangeably really.
What is the reason for having two different letters for the same "u" sound?
And ortography: Ó <--> O; IÓ <--> IE, Ó <--> A
ósmy - osiem - 8th - 8
siódmy - siedem - 7
szósty - sześć - 6
zawrócić - zawracać - turn back
But there is a lot more, because e.g. dwunasty - dwanaście = 12 or dwudziesty - dwadzieścia =20; dwusetny - dwieście = 200. It's remainder after dual form in Polish.
Children want to make U and Ó one letter :) Personally I think that we have more words that have uninflected Ó than inflected.