mother with four kids.
mother with eight kids.
THEY KNOW EXACTLY HOW TO SAY THESE IN ENGLISH,
AND IT IS USUALLY EASY FOR THEM, but
you will be shocked to notice that you will hear a lot of versions
for these told in POLISH, and none of them will be correct....
I think you may be right. As for the first two examples, these are rarely used or not used at all. But the last two examples are not so unusual (I mean the declension of the numeral with the plural noun "dzieci"), so most people should be
OK with them. The trick here which most people may not be aware of is that all nouns in your example fall into the same gramatical category for the purpose of numeral declension: neutral nouns or only-plural nouns. Other examples of that kind may be: troje sań, czworo drzwi, pięcioro okien
, though I dare say quite a number of Polish people, if not most of them, will be inclined to say: trzy sanie, cztery drzwi, pięć okien. I myself "feel" pięcioro okien
as a little bizzare form, as opposed to pięć okien
which seems all right to me, but is not).