"Mis padres conocen Alemania."
Translation:My parents know Germany.
Just to clarify... being 'familiar' with a country means you know your way around geographically and culturally.
When you know a person you have to use the personal a. But not with things like countries
It would also not use conocer. At least not if you go for the common meaning of "to know a language".
- My parents know German. - Mis padres saben (hablar) alemán.
This is a strange sentence. "My parents know Germany well" would sound more natural.