Der Junge stolpert über den Ast und fällt auf den Boden.

and

Breakdown of Der Junge stolpert über den Ast und fällt auf den Boden.

• fallen: to fall
• auf: onto
• der Boden: the ground

Questions & Answers about Der Junge stolpert über den Ast und fällt auf den Boden.

Why is it der Junge but den Ast?

Because der Junge is the subject of the sentence, so it is in the nominative case. Den Ast is the thing affected by the action stolpert über, so it is in the accusative case.

Both Junge and Ast are masculine nouns, so their definite articles change like this:

• nominative: der
• accusative: den

So:

• der Junge = the boy
• den Ast = the branch

Why is it über den Ast and not über dem Ast?

Über is a two-way preposition, which means it can take either:

• accusative for direction/movement toward or across
• dative for location

Here, the expression is über etwas stolpern = to trip over something, and it normally uses the accusative.

So:

• über den Ast stolpern = to trip over the branch

Using über dem Ast would sound like a location idea such as above the branch, which is not what is meant here.

Why is it auf den Boden and not ?