Breakdown of Þeir voru að rannsaka hótelið.
vera
to be
þeir
they (m)
að
to (infinitive marker)
hótelið
the hotel
Questions & Answers about Þeir voru að rannsaka hótelið.
How does the past continuous structure work in this sentence?
The past continuous is formed using the past tense of vera (to be) plus að plus the infinitive verb. Here, voru is 'were' and að rannsaka is 'investigating', showing an action that was ongoing in the past.
Would it mean the same thing if I said Þeir rannsökuðu hótelið?
Not quite! Þeir rannsökuðu is the simple past and means 'They investigated.' Using voru að rannsaka emphasizes that the action was currently happening at that moment in the past, just like 'were investigating' in English.
Why does the sentence use Þeir for 'they' instead of Þau?
What case is hótelið in here?
It is in the accusative case because it is the direct object receiving the action of rannsaka (to investigate). Because hótel is a neuter noun, its accusative form looks exactly the same as its dictionary form. The -ið at the end is the attached definite article meaning 'the'.