Breakdown of Ein stärkerer Beweis ist gesichert worden.
sein
to be
ein
a, an (eine)
stark
strong
werden
to be (passive auxiliary + past participle)
Questions & Answers about Ein stärkerer Beweis ist gesichert worden.
Why do we use ist here instead of hat for the Perfekt tense?
In the active voice, the Perfekt tense of many verbs uses haben (e.g., Er hat den Beweis gesichert). However, the passive voice in the Perfekt tense always uses sein as the helper verb. The formula is sein + past participle + worden. Since Beweis is singular, we use ist.
Why does stärkerer have such a long ending?
It is a comparative adjective doing double duty! The base word for stronger is stärker. Since Beweis is a masculine noun in the nominative case (the subject), and the article ein does not show the masculine gender, the adjective must take the strong masculine ending -er. So you get stärker + er = stärkerer.
I learned that the past participle of werden is geworden. Why is it just worden here?
When you use werden as a helper verb to build the passive voice in the Perfekt tense, the ge- prefix is dropped. German does this to avoid the clunky sound of having two past participles with ge- right next to each other (like gesichert geworden).
Is gesichert worden the only way to describe a past passive action?