"Moja siostra i ja podróżujemy za granicę."
Translation:My sister and I are travelling abroad.
just wondering - in this sentence, the word granica is spelled with a final "e" with an ogonek. I thought that the preposition "za" would necessitate the instrumental case, and therefore the final vowel of granica would convert to an "a" with an ogonek. Elsewhere in this lessen, there is a question : "Jesteś za granicą?" in which case the "a" with an ogonek is used. Would you please clarify for me?