Learn German: Das Hotel ist teuer, denn es ist neu. - The hotel is expensive, because it is new.

denn (because) is a coordinating conjunction, which means it sits in what we call Position 0. It glues two normal sentences together without changing their word order. So, in the second half, the subject es takes Position 1 and the verb ist stays in its normal Position 2.

Why do we use es in the second part?

es means 'it' and is used here to refer back to Das Hotel. Since Hotel is a neuter noun (it uses das), we must use the neuter pronoun es. If the noun had been masculine, we would have used er.

Do I always need a comma before denn?

Yes! In German, you must always place a comma before denn when it connects two complete thoughts (independent clauses). This is a strict rule in German punctuation, unlike in English where commas before 'because' are often optional.

Is denn a formal way to say 'because'?

Not at all! denn is very common in everyday German. It structurally works like the English word 'for' when giving a reason, but it feels completely natural and modern. It is also the easiest way for beginners to say 'because' since it keeps your verb safely in Position 2!