Questions & Answers about Der Hund rennt durch den Park.
Why does the sentence use den Park instead of der Park?
The word durch (through) is a preposition that always requires the accusative case. Since Park is a masculine noun (der Park), its 'the' word changes to den in the accusative.
Because the dog is moving, is that why we use the accusative case here?
No, the movement actually doesn't matter for the word durch. Unlike two-way prepositions (like in or auf) which change case depending on whether there is movement toward a destination, durch is strictly an accusative preposition. It always takes the accusative case, even if nothing is moving!
Can durch den be combined into one short word?
Not in this case. The words durch and den remain separate. However, if the noun is neuter, like das Tor (the gate), you can combine durch and das into the short form durchs (for example, durchs Tor).
Can I use laufen instead of rennen in this sentence?
Yes, you could say Der Hund läuft durch den Park. In German, laufen can mean both walking and running, depending on the context. The word rennen is just more specific and emphasizes a fast run or sprint.