What's the difference between the plural of "kous - kousen" and "neus-neuzen"?
Why the plural of 'kous' ended with 's' like in the 'kousen' and why 'neus' ended with 'z' like in the 'neuzen'? How to determine between using 's' or change the 's' becomes 'z'?

Question

Answer

If a word ends with "ns" the s remains.
- kans (chance) --> kansen

In other circumstances the "s" usually changes into "z".
But "kous" seems to be an exception.
Dutch is a very irregular language unfortunately.

Answer

Here is a website which explains this, and yes, Dutch is a difficult language because its not always consistent, there are many exeptions to the rule...good luck with studying Dutch!

https://onzetaal.nl/taaladvies/advies/kaarsen-laarzen