Breakdown of Der Herzog vergiftet den König und übernimmt dessen Thron.
und
and
der König
the king
übernehmen
to take over
der Herzog
the duke
Questions & Answers about Der Herzog vergiftet den König und übernimmt dessen Thron.
Why do we use dessen here instead of seinen?
If the sentence used seinen Thron, it would be ambiguous: it could mean the duke poisoned the king and then took over his own (the duke's) throne. Using dessen points specifically to the last mentioned person, which is den König, making it completely clear whose throne was taken.
Why doesn't dessen have an accusative ending to match the direct object Thron?
Unlike normal possessive adjectives like sein (which would become seinen to match the accusative masculine Thron), the demonstrative possessives dessen and deren never take endings to match the thing being possessed. They only reflect the gender and number of the possessor. Since the possessor is the masculine König, we use dessen.
Why doesn't the prefix über go to the end of the sentence?
The verb übernehmen (to take over) is an inseparable verb. Even though über can sometimes be a separable prefix with other verbs, here it stays permanently attached to the verb stem, which is why it is übernimmt and not nimmt ... über.
What if the possessor was feminine, like a queen? Would we still use dessen?