Yes! The existence of a five-legged dog makes “all dogs have four legs” false but it doesn’t make “dogs have four legs” false. Similarly, the existence of a two

Yes! The existence of a five-legged dog makes “all dogs have four legs” false but it doesn’t make “dogs have four legs” false. Similarly, the existence of a two-legged dog makes “some dogs have only two legs” true while “dogs have two legs” is still not (unless you just mean the former). Dog is a categorical abstraction over individuals. The properties of a category tend to have a complex relationship to the members of the category. This is true even if it is indisputable who the members are and what properties the members have.