dass vs weil in German
Pick dass for content and weil for reasons, and switch between weil and denn without word-order mistakes.
dass introduces what someone says, thinks or knows. weil gives a reason and answers the question warum?
Both send the verb to the end, so the only choice is about meaning.
dass = what, weil = why
- dass follows verbs like sagen, denken, wissen, hoffen.
- weil answers the question warum?
- Can you say 'because'? Then use weil.
Typical verbs before dass
- saysagen
- thinkdenken
- believeglauben
- knowwissen
- hopehoffen
- findfinden
- be gladfroh sein
Ich hoffe, dass du bald wieder gesund bist.
I hope that you'll be well again soon.
Ich bleibe im Bett, weil ich Fieber habe.
I'm staying in bed because I have a temperature.
When English drops 'that'
English often leaves out 'that'. German can drop dass after verbs like glauben or sagen, but then the verb goes back to position 2.
Ich glaube, dass er morgen kommt.
I think he's coming tomorrow.
Ich glaube, er kommt morgen.
I think he's coming tomorrow.
weil or denn?
Both mean 'because'. weil sends the verb to the end, denn keeps it in position 2.
- Only a weil clause can come before the main clause.
- Only weil works as a short answer to warum?
Wir nehmen ein Taxi, weil es regnet.
We're taking a taxi because it's raining.
Wir nehmen ein Taxi, denn es regnet.
We're taking a taxi, as it's raining.
Common mistakes
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Ich denke, weil das Hotel gut ist.✓ Ich denke, dass das Hotel gut ist.
Content after denken takes dass, not weil.
✗
Denn ich müde bin, gehe ich schlafen.✓ Weil ich müde bin, gehe ich schlafen.
A denn clause can't come first; use weil.
✗
Warum lernst du Deutsch? – Denn ich wohne hier.✓ Warum lernst du Deutsch? – Weil ich hier wohne.
Short answers to warum need weil and verb last.
Questions learners ask
Can I leave out dass in German?
Yes, after verbs like glauben, denken or sagen. The clause then uses main-clause order: Ich glaube, er kommt.
Is denn more formal than weil?
Slightly. In speech weil is far more common, while denn is typical of written German.