"We are not mice."
Translation:Wij zijn geen muizen.
its not quite as simple as just saying niet negates a verb and geen negates a noun-- using this as a rule is confusing because geen is used in situations where a verb is a key part of the phrase-- like here. A more reliable way to remember it is to look at the article with the noun. If you look at this phrase, "we are not mice," youll see mice has no article, meaning the noun is in its indefinite form. When the noun in a phrase is indefinite, youll use geen. i.e. "Im not a mouse!/We are not mice!". You arent saying youre not a specific mouse, just that you arent a mouse in general, so you negate it using geen. Its a completely arbitrary distinction to english speakers, as the use of no and not is more dynamic in our language :) as a simpler rule, niet is used in more complex phrases that use grammar concept you wont learn for a little while-- by then youll be an expert of distinguishing when to use geen and niet!