Breakdown of Der Roman, den du liest, hat ein langweiliges Ende.
ein
a, an (eine)
du
you (informal singular)
haben
to have
lesen
to read
Questions & Answers about Der Roman, den du liest, hat ein langweiliges Ende.
Why do we use den here instead of der?
den is the relative pronoun pointing back to Der Roman (which is masculine). Inside the relative clause (den du liest), the novel is the direct object because it's the thing you are reading. Since it is a masculine noun acting as the direct object, we use the accusative form den.
Why is the verb liest at the end of the phrase between the commas?
den du liest is a relative clause. In German, relative clauses always push their conjugated verb to the very end of the clause, right before the comma that closes it.
Why does the sentence continue with hat right after the second comma?
The relative clause (den du liest) interrupts the main sentence to add more information. If you take it out, the core sentence is just Der Roman hat ein langweiliges Ende. After the relative clause finishes, the main sentence simply picks up exactly where it left off.
Why does the adjective langweiliges end in -es?
Ende is a neuter noun (das Ende). Here, it comes after the word ein. Because ein doesn't show the neuter gender clearly on its own, the adjective has to step up and show the gender by taking the neuter ending -es.