Breakdown of Wir müssten die Polizei anrufen oder den Notruf wählen.
wir
we
müssen
to have to, must
anrufen
to call (by phone)
oder
or
Questions & Answers about Wir müssten die Polizei anrufen oder den Notruf wählen.
Why is it müssten instead of müssen?
müssen means we must or we have to. müssten is the Konjunktiv II (conditional) form, which translates to we would have to. It makes the statement hypothetical, like a cautious suggestion rather than a strict command.
I thought anrufen splits into two parts. Why is it all one word here?
You are right that anrufen is a separable verb (like in ich rufe an). However, because we are using the modal verb müssten, the action verb gets pushed to the very end of its phrase in its full dictionary form (infinitive). So the prefix stays attached as anrufen.
Why does the sentence use den Notruf instead of der Notruf?
The word for emergency call is masculine: der Notruf. Because it is the direct object of the sentence (the thing you are dialing), it takes the accusative case, so der changes to den.
How does the word oder affect the sentence structure here?
oder (or) is a coordinating conjunction that connects two equal parts of a sentence without changing the word order. Here, it links two actions that share the same subject and modal verb: die Polizei anrufen and den Notruf wählen. You can think of the second part as a shortened version of saying oder wir müssten den Notruf wählen.