what is it?
German offers two parallel ways to express a temporal relationship between two events: a subordinate clause introduced by a temporal conjunction (e.g. nachdem, während, bevor, seit, bis), or a prepositional noun phrase built from the corresponding preposition plus a noun or nominalized infinitive (e.g. nach dem Essen, beim Einsteigen, vor der Abreise). The two structures are largely interchangeable in meaning; the choice is driven by register, economy, and whether the subject of both clauses is the same. Stand-alone adverbs such as vorher/zuvor and danach/anschließend provide a third option: they link two separate sentences without any subordination at all.
when to use it
Use a subordinate clause when the two events have different subjects, or when the event itself is too complex to compress into a single noun. The conjunction must match the temporal relation: nachdem (after), bevor/ehe (before), während (while), seit(dem) (since), bis (until).
Use a prepositional noun phrase when both events share the same subject, or in formal and written registers where nominal style is preferred. The preposition governs a specific case: während + genitive (formal) or dative (colloquial); vor, nach, seit, bis zu + dative; bei + dative (often with a nominalized infinitive) for simultaneity.
Use a sentence adverb (vorher, zuvor, danach, anschließend) when you want to keep two events as separate sentences and simply signal their sequence. This is common in spoken language and informal writing.
formation
The table below maps each temporal conjunction to its prepositional counterpart and the case it requires.
| conjunction (+ clause) | preposition (+ noun phrase) | case | meaning |
|---|---|---|---|
| nachdem | nach | dative | after |
| bevor / ehe | vor | dative | before |
| während | während | genitive (formal) / dative (colloquial) | while / during |
| seit(dem) | seit | dative | since |
| bis | bis zu | dative | until |
| während (simultaneity) | bei | dative | while (doing sth.) |
When converting a clause to a noun phrase, the verb is typically replaced by a nominalized infinitive (neuter, capitalized: das Essen, das Einsteigen, das Packen) or by a related noun (die Abreise, die Ankunft). The article and any adjective must agree with the noun in the required case.
bei + nominalized infinitive is the standard way to express simultaneity when the subject is the same in both events: beim Einsteigen = während man einsteigt. The contraction bei + dem → beim is obligatory.
examples in context
common pitfalls
Using a preposition directly with a full clause. A preposition cannot introduce a finite verb. *nach wir gegessen hatten is ungrammatical. Either use the conjunction nachdem wir gegessen hatten or the noun phrase nach dem Essen.
Confusing the conjunction nachdem with the preposition nach. nachdem introduces a subordinate clause and sends the verb to the end: Nachdem wir gegessen hatten, …. nach is a preposition and governs a noun phrase in the dative: nach dem Essen. They are not interchangeable.
Wrong case in the nominal variant. vor, nach, seit, bis zu all require the dative: nach dem Essen (not *nach das Essen). während takes the genitive in formal written German: während des Essens (not *während dem Essen in formal style).
Three sentences, graded here. Nothing is saved and no account is needed.
Während ___ sprachen die Gäste laut über das Rezept. (Abendessen)
Fill in the blank with the correct form of the noun in parentheses to complete the temporal phrase.