"We have some white cats."
Translation:Vi har noen hvite katter.
Adjectives need to agree with the gender and number of noun they're describing:
indefinite singular m/f: hvit
indefinite singular n: hvitt
definite singular m/f/n: hvite
all plurals: hvite
Yes, that's what I'm saying.
I'm sure it must seem so to someone whose native language is English, but it's actually not all that uncommon. :)