Breakdown of Als der Aufzug feststeckte, waren wir plötzlich eingesperrt.
sein
to be
wir
we
plötzlich
suddenly
als
when (past single event)
Questions & Answers about Als der Aufzug feststeckte, waren wir plötzlich eingesperrt.
Why do we use als for "when" instead of wenn?
In German, als is used for a single, one-time event in the past (the specific moment the elevator got stuck). If you wanted to say "whenever the elevator got stuck" to describe a repeated past event, you would use wenn.
feststecken is a separable verb. Why isn't it separated as steckte fest here?
Subordinating conjunctions like als kick the conjugated verb to the very end of the clause. Because the prefix (fest-) is already waiting at the end, the conjugated part (steckte) simply reconnects with it, forming the single word feststeckte.
Is waren ... eingesperrt considered passive voice?
Yes, this is the "state passive" (Zustandspassiv). It is formed with sein (here in the past as waren) plus the past participle (eingesperrt) to describe a resulting state. If the sentence used wurden eingesperrt (action passive), it would mean someone was actively locking them in at that exact moment. Here, it just describes their condition of being trapped.
How could we use imstande sein (from this lesson) to add that we were "unable to free ourselves"?