Present perfect passive (er blevet)

When talking about a recently completed action where the result matters more than who did it, Danish uses the present perfect blive-passive.

To form it, use er blevet followed by the past participle of the main verb. Notice that Danish uses er (is) rather than har (has) as the helper verb.

The long tunnel under the river has been constructed.
Den lange tunnel under floden er blevet anlagt.
The new bike lane has been constructed near the school.
Den nye cykelsti er blevet anlagt i nærheden af skolen.

If the verb has a particle, such as rive ned (to demolish), the particle follows the past participle.

The old factory by the subway has been demolished.
Den gamle fabrik ved metroen er blevet revet ned.

This structure works exactly the same way in subordinate clauses.

He believes that the subway has been expanded.
Han tror at metroen er blevet udvidet.
She says that the sidewalk has been widened.
Hun siger at fortovet er blevet udvidet.

Er blevet or blev?

The choice usually works as in English. Er blevet is for a result you see now, with no past time named; when you say when it happened (i går, sidste år), use the simple past blev: Cykelstien blev fjernet sidste år.

The old house in front of the fountain has been demolished.
Det gamle hus foran springvandet er blevet revet ned.

The perfect is also how you report a change someone has noticed:

The children say that the intersection has been repaired.
Børnene siger at krydset er blevet repareret.

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