In D’Ooge’s Latin For Beginners we are asked to translate “My friend is from a village of Germany, my fatherland”. I believe that this should be “Amicus est ex vico Germaniae, mea patria” but the key has “meae patriae” for the second clause. Why would it be appropriate for this to be genitive?
If it were in the nominative how would mea patria connect with the rest of the sentence?
Have a look at rule 81 on page 30 (?). “Germaniae” is in apposition to “meae patriae”. “Nouns so related that the second is only another name for the first and explains it are said to be in apposition, and are always in the same case.”
This is a good illustration of the difference between Latin and English. Because English is not as inflected as latin one can put nouns in apposition without worrying about the case. To make sense of this one relies on word order. Latin is a highly inflected language and so nouns in apposition have to be grammatically connected and share the same case.
Edit
Did you fully understand “Rhenus est in Germania, patria mea” ? What case is “Germania” and “patria mea”?
From “Rhenus est in Germania, patria mea” I got some vague idea about patria mea being nominative because it was in a different clause. I didn’t make the connection that patria mea was an appositive there. Now I understand, thanks.