Wegen vs. aufgrund vs. dank
The German words wegen, aufgrund, and dank all translate to because of or due to, but they are not interchangeable. The key difference lies in their connotation and level of formality, with wegen being neutral, aufgrund being formal and factual, and dank being explicitly positive.
Wegen
A2This is the most common and neutral preposition for because of or due to. It can be used in almost any context, whether the cause is positive, negative, or neutral. It is the standard, everyday choice and is often followed by the genitive case in written German, but the dative case is very common in spoken, colloquial German.
Die Straße ist wegen Bauarbeiten gesperrt.
(The street is closed because of construction work.)
Wegen des schlechten Wetters wurde das Festival abgesagt.
(Because of the bad weather, the festival was canceled.)
Ich rufe wegen Ihrer Anzeige in der Zeitung an.
(I am calling because of your advertisement in the newspaper.)
Er konnte wegen einer wichtigen Besprechung nicht kommen.
(He could not come because of an important meeting.)
Wegen dem Stau kam ich zu spät zur Arbeit.
(Because of the traffic jam, I arrived late for work.)
Aufgrund
B2This preposition means on the grounds of or due to and is more formal and objective than wegen. It is typically used in written, official, or professional contexts to point to a verifiable fact, piece of evidence, or a solid foundation as the reason for something. It is always followed by the genitive case.
Aufgrund neuer Beweise wurde der Fall wieder aufgenommen.
(Based on new evidence, the case was reopened.)
Der Flug wurde aufgrund eines technischen Problems annulliert.
(The flight was canceled due to a technical problem.)
Aufgrund der hohen Nachfrage sind die Tickets leider ausverkauft.
(Due to high demand, the tickets are unfortunately sold out.)
Ihre Bewerbung wurde aufgrund fehlender Qualifikationen abgelehnt.
(Your application was rejected on the grounds of missing qualifications.)
Aufgrund seiner langjährigen Erfahrung wurde er zum Teamleiter befördert.
(Due to his many years of experience, he was promoted to team leader.)
Dank
B1This preposition means thanks to and is used exclusively to express a positive cause. It highlights that a desirable outcome was achieved because of the helpful influence of a person, thing, or situation. It can be used with either the dative or the genitive case.
Dank deiner schnellen Hilfe haben wir den Zug noch erwischt.
(Thanks to your quick help, we still caught the train.)
Wir fanden den Weg sofort dank des modernen Navigationssystems.
(We found the way immediately thanks to the modern navigation system.)
Dank des sonnigen Wetters war der Ausflug ein voller Erfolg.
(Thanks to the sunny weather, the trip was a complete success.)
Das Unternehmen konnte dank einer neuen Strategie wachsen.
(The company was able to grow thanks to a new strategy.)
Dank seiner Geduld konnte er das komplizierte Rätsel lösen.
(Thanks to his patience, he was able to solve the complicated puzzle.)
Summary
To summarize the difference: use wegen for neutral, everyday reasons (because of). Use aufgrund for formal, factual, and evidence-based reasons (due to, on the grounds of). Use dank only for positive reasons where you are grateful for the cause (thanks to).