Breakdown of Jag trodde att det näst högsta vattenfallet låg i Afrika.
jag
I
i
in
tro
to believe
det
the (with ett-words)
Questions & Answers about Jag trodde att det näst högsta vattenfallet låg i Afrika.
How does näst högsta work to mean second highest?
näst literally means next. When you place it directly before a superlative adjective like högsta (highest), it steps the rank down by one. Therefore, the next highest becomes the second highest.
Why is the adjective högsta used here instead of the basic superlative högst?
Because it is part of a definite noun phrase. The sentence uses the definite article det (the), which forces the superlative adjective into its definite form by adding an -a. Notice that the noun vattenfallet also takes its definite ending.
Why use låg instead of var if the English translation is was located?
låg is the past tense of att ligga (to lie or be situated). In Swedish, when talking about the permanent geographical location of places, buildings, or natural features like waterfalls, it is much more natural to use ligga rather than vara (to be).
The waterfall is presumably still in Africa, so why use the past tense låg?
This is due to sequence of tenses. Because the main verb of the sentence, trodde (thought), is in the past tense, the verb in the subordinate att-clause is pulled into the past tense to match it, even though the geographical fact remains true today.