The differences between "denn" and "weil" are syntactic only. "Denn" introduces a main clause, which is why, as you say, it "doesn't change the sentence structure". The finite verb remains in second position. "Weil" introduces a subordinate clause, so the finite verb is moved to the end of the clause. Another notable syntactic difference is that you cannot begin a sentence with a main clause ...
The reason why the distinction between "denn" and "dann" is diffcult even for Germans lies in their common etymology: dann Adv. und denn Adv. und Konj. sind ursprünglich umlautlose und umgelautete Form eines Wortes und daher in älterer Zeit bedeutungsgleich. Ahd. thanne, thenni (8. Jh.), mhd. dan (ne), den (ne), frühnhd. dann, denn Adv. und ...
Every so often, I see someone use "denn" in a question, but I do not know why. Some examples: Was hörst du denn für Musik? Was machst du denn? What is the point of this, and what does i...
sentence structure - What does "denn" mean in this context? - German ...
Can you please tell me if there is any difference in meaning between denn and eigentlich when asking questions? For example: Was machst du denn beruflich? Was machst du eigentlich beruflich?
word choice - Is there any difference in meaning between "denn" and ...
4 In the following sentence, is the word order after "denn" correct? I thought that after the word "denn", the verb is supposed to be in the second position? Als Hassobjekt war er beständiger als Eurasien oder Ostasien, denn wenn Ozeanien mit einer dieser Mächte Krieg führte, hielt es mit der anderen gemeinhin Frieden.