This is the 454th most frequent Croatian word.
njemačkoj
The Croatian word "njemačkoj" means "to Germany" or "in Germany" (dative or locative case of "Njemačka").
'Njemačkoj' is used here as the dative form of the proper noun 'Njemačka', representing the country Germany. The dative case is used because the preposition 'u' (in) requires the locative case for specifying places when referring to location, and for this particular noun, the dative and locative forms are the same.
Živjela sam u Njemačkoj tri godine.
I lived in Germany for three years.
'Njemačkoj' is used in the locative case here which is required by the preposition 'o' (about) to indicate the subject of discussion.
Razgovarala sam s prijateljem o Njemačkoj.
I talked to a friend about Germany.
'Njemačkoj' appears here again in the dative/locative case because the context involves the planning of an action related to a place, and the specific form aligns with the grammatical structure of the sentence.