Translation:My grandmother and grandfather are Finns.
I guess the point of this sentence is teaching the noun finländare (Finn) rather than the adjective finländsk (Finnish).
I've learned that finnar means Finns (people of Finnish culture and language), while finländare means Finlanders (people of Finland including the Fenno-Swedes). Is that correct, or does that distinction perhaps only exist in Finland?
It does exist in Sweden too, but Swedes usually don't practice the difference to the extent that Finlanders do.
Can someone explain when to capitalise names? I feel like it changes in every sentence, sometimes it's Tyskland, then tyskland, it's Stockholm, then stockholm. Are both correct?
This sentence does not accept gran and grandad instead of grandmother snd gramdfather. It is much more common to use gran and grandad.