Breakdown of Они выбирают альтернативный маршрут в связи с долгой задержкой.
они
they
выбирать
to choose
долгий
long (of time)
маршрут
route
Questions & Answers about Они выбирают альтернативный маршрут в связи с долгой задержкой.
How does the phrase в связи с affect the grammar of the words that follow it?
The compound preposition в связи с translates to "due to" or literally "in connection with." The с ("with") part dictates the case, so it requires the Instrumental case. That is why the feminine phrase долгая задержка (long delay) changes to долгой задержкой.
Could I just say из-за долгой задержки instead of в связи с долгой задержкой?
Yes, structurally you could use из-за + Genitive, and it means almost the same thing. However, в связи с sounds much more formal and official. You will frequently hear в связи с in formal announcements, news reports, or transportation updates (like train or flight delays), whereas из-за is what you would normally use in everyday conversation.
Why is the imperfective verb выбирают used here?
The imperfective выбирают is used to show an ongoing action in the present tense: "they are choosing". If they had already made the choice, you would use the perfective past выбрали ("they chose"). If you used the perfective future form выберут, it would mean "they will choose".
Is маршрут in the Nominative case here? It doesn't look like its ending changed.