You already know how to form the present passive voice using worden and a past participle. You also know how to use modal verbs like moeten (must), kunnen (can), zullen (will), and mogen (may). When discussing rules, repairs, or plans, you will often need to combine these two concepts.
Passive with modals in main clauses
When you use a modal verb in the passive voice, the modal verb becomes the conjugated verb. It takes the standard second position in a main clause.
The verb worden is used in its full infinitive form and gets pushed to the very end of the sentence, immediately following the past participle.
| The sewer must be inspected today. | Het riool moet vandaag worden geïnspecteerd. |
| The crack in the street can be reported online. | De scheur in de straat kan online worden gemeld. |
Using other modal verbs
This structure works exactly the same way for making predictions with zullen or expressing permission and prohibition with mogen. Just conjugate the modal in the second position and keep the [past participle] + worden cluster at the end.
| A new traffic sign will be placed here. | Er zal hier een nieuw verkeersbord worden geplaatst. |
| The maintenance on the sewer may not be forgotten. | Het onderhoud aan het riool mag niet worden vergeten. |
Subordinate clauses
When combining a modal verb and the passive voice in a subordinate clause (such as after omdat or dat), all the verbs get pushed to the end of the clause.
A common and natural order for this verb cluster at the end of a subordinate clause is [modal verb] + worden + [past participle].
| The road is closed, because the asphalt must be removed. | De weg is afgesloten, omdat het asfalt moet worden verwijderd. |
| The municipality says that the bridge must be better maintained. | De gemeente zegt dat de brug beter moet worden onderhouden. |