Learn German: Das Lektorat, welches den Text prüft, arbeitet schnell. - The editorial department, which checks the text, works fast.

welches is a formal, written alternative to the standard relative pronoun das. It means exactly the same thing in this context. Writers often use welcher, welche, or welches to sound more elevated or to avoid repeating der, die, or das too many times in a single sentence.

Why is the relative pronoun in the neuter nominative form (welches)?

Like all relative pronouns, it takes its gender from the noun it refers back to: das Lektorat is neuter. Its case is determined by its job in the relative clause. Here, the editorial department is the one doing the checking (prüft), so it acts as the subject (nominative case).

Would it be natural to say this sentence out loud using welches?

Not usually. While grammatically correct, using welches as a relative pronoun in everyday speech sounds very stiff and overly formal. If you were talking to a colleague, you would almost certainly use das instead: Das Lektorat, das den Text prüft, arbeitet schnell.

What exactly is das Lektorat?