Subordinate clauses with "weil" and "dass"

Weil ("because") and dass ("that") are two of German's most common subordinating conjunctions. Unlike the coordinating conjunctions und, aber, oder, denn, and sondern, a subordinating conjunction does change word order — quite dramatically: the finite verb moves all the way to the end of its clause.

Quick shortcut: after weil or dass, push the finite verb to the very end of the clause, and always use a comma between the main clause and the weil/dass clause. Sie bleibt zu Hause, weil sie krank ist. — not …, weil sie ist krank.

Weil: giving a reason

Weil introduces a reason, just like denn — but with completely different word order:

• Sie bleibt zu Hause, weil sie krank ist. (She's staying home because she's sick.)
• Ich lerne Deutsch, weil ich in Berlin arbeite. (I'm learning German because I work in Berlin.)
• Er kommt nicht, weil er keine Zeit hat. (He's not coming because he doesn't have time.)

Compare this to denn, from Coordinating conjunctions: Sie bleibt zu Hause, denn sie ist krank. Same meaning, same reason — but denn leaves the verb in its normal second position, while weil sends it all the way to the end.

(In casual spoken German, you'll sometimes hear weil used with normal second-position word order too — weil sie ist krank — almost as if it were denn. It's common in relaxed speech, but verb-final order is what's expected in writing and in careful spoken German, so that's the form to produce.)

Dass: reporting a fact or statement

Dass introduces a fact, opinion, or statement — usually after a verb like glauben (to believe), wissen (to know), sagen (to say), hoffen (to hope), or a phrase like es ist wichtig (it's important):

• Ich glaube, dass er recht hat. (I believe that he's right.)
• Ich weiß, dass sie in München wohnt. (I know that she lives in Munich.)
• Es ist wichtig, dass du pünktlich kommst. (It's important that you come on time.)

The verb always goes to the end

In a normal main clause, the finite verb sits in second position. In a weil- or dass-clause, it moves to the very end instead — everything else about the clause (subject, objects, time/place details) stays in the same relative order, just with the verb pushed past all of it:

• Er hat keine Zeit. → …, weil er keine Zeit hat.
• Sie wohnt in München. → …, dass sie in München wohnt.
• Du kommst morgen pünktlich an. → …, dass du morgen pünktlich ankommst. (with a separable verb, the two parts reunite at the very end: an + kommst → ankommst)

When the weil/dass-clause comes first

A weil-clause (less commonly a dass-clause) can also open the sentence. When it does, the whole subordinate clause counts as the main clause's first position, from Word order: the verb in second position — so the main clause's verb comes immediately after the comma, ahead of its own subject:

• Weil sie krank ist, bleibt sie zu Hause. (Because she's sick, she's staying home.)
• Weil ich in Berlin arbeite, lerne ich Deutsch. (Because I work in Berlin, I'm learning German.)

The comma itself doesn't move — it always sits at the boundary between the two clauses. It's only which side of weil/dass the comma ends up on that changes: right before it when the subordinate clause comes second, right after the whole subordinate clause when it comes first.

Common mistakes

• ❌ Sie bleibt zu Hause, weil sie ist krank. → ✅ Sie bleibt zu Hause, weil sie krank ist. (the verb belongs at the very end, not in second position)
• ❌ Ich glaube dass er recht hat. → ✅ Ich glaube*,** dass er recht hat.* (a comma always separates the two clauses, here right before dass, just like before weil)
• ❌ Weil sie krank ist, sie bleibt zu Hause. → ✅ Weil sie krank ist, bleibt sie zu Hause. (when the weil-clause comes first, the main clause's verb comes right after the comma)
• ❌ Sie bleibt zu Hause, weil sie ist krank, denn sie ist krank. → ✅ Sie bleibt zu Hause, weil sie krank ist. (mixing up weil's verb-final order with denn's normal order is the single most common error at this stage)

Quick check

Put the verb in the right place: end of the clause, or right after the comma?

1. Ich bleibe zu Hause, weil ich krank ___. (sein)
2. Weil es regnet, ___ wir zu Hause. (bleiben)
3. Ich weiß, dass er heute ___. (arbeiten)
4. Sie sagt, dass sie das Buch ___. (lesen)

Key takeaways

• Weil ("because") and dass ("that") are subordinating conjunctions: they send the finite verb all the way to the end of their clause.
• Weil gives a reason, just like denn — but denn leaves word order untouched, while weil moves the verb to the end.
• Dass reports a fact or statement, usually after verbs like glauben, wissen, sagen, or phrases like es ist wichtig.
• A comma always separates the main clause from the weil/dass clause — before weil/dass when the subordinate clause comes second, after it when it comes first.
• If the weil-clause comes first, it counts as the main clause's first position, so the main clause's verb comes immediately after the comma.
• Verb-second order after weil (like denn) turns up in casual speech, but verb-final order is the standard form to produce.