The Perfect Passive with Modal Verbs
To express what had to be done in the past, you can use the simple past (musste repariert werden) or the present perfect (Perfekt).
To form the perfect passive with a modal verb, use a unique structure called the "double infinitive":
- The conjugated auxiliary verb haben takes Position 2.
- The action is described by a three-verb cluster at the end of the sentence: the Past Participle + werden
- the Modal Infinitive.
| In the indoor ice rink, the cooling system has had to be completely replaced. | In der Eishalle hat das Kühlsystem komplett ersetzt werden müssen. |
Subordinate Clauses
In a standard subordinate clause (like those starting with weil or dass), the conjugated verb goes to the very end. However, with this double infinitive structure, the conjugated haben does not go to the end. Instead, it is placed immediately in front of the verb cluster.
| It is about safety, because the deep crack in the ice surface has had to be mended. | Es geht um die Sicherheit, weil der tiefe Riss in der Eisfläche hat ausgebessert werden müssen. |
More Examples
In a main clause, haben stays in Position 2, even after a connecting adverb like deshalb.
| The procedure is elaborate, therefore the ice surface has had to be smoothed with the ice machine. | Das Verfahren ist aufwendig, deshalb hat die Eisfläche mit der Eismaschine geglättet werden müssen. |
Conjugate haben based on the subject receiving the action. For a plural subject, use haben:
| Many cracks have had to be mended and smoothed. | Viele Risse haben ausgebessert und geglättet werden müssen. |
Whether asking a question or stating a fact, the rule for subordinate clauses remains the same: the conjugated form of haben sits in front of the three-verb cluster.
| Is it true that the crack in the cooling system has had to be extensively repaired? | Ist es wahr, dass der Riss im Kühlsystem aufwendig hat repariert werden müssen? |