Breakdown of Кабина должна быть закреплена до начала работы.
работа
work, job
быть
to be
начало
beginning
должен
must, have to (должен, должна, должны)
Questions & Answers about Кабина должна быть закреплена до начала работы.
Why do both должна and закреплена end in "-а"?
They both agree with the feminine singular subject, кабина. In this passive construction, the modal word (должен) and the short passive participle must both match the gender and number of the subject they refer to.
What verb does закреплена come from, and why is it used here?
It is the short past passive participle of the perfective verb закрепить (to secure or fasten). In Russian, passive constructions expressing a required result or completed state use быть plus the short form of a perfective participle.
Could we use a reflexive verb like кабина должна закрепляться instead?
You could, but it shifts the focus. Using the imperfective reflexive (закрепляться) emphasizes the ongoing action or routine of someone securing it. The construction должна быть закреплена focuses purely on the completed result: the cabin must be in a fully secured state before work can begin.
Why are there two genitive words in a row at the end of the sentence: начала работы?
The preposition до (before) requires its object to be in the genitive case, turning начало (start) into начала. The second word, работы, is in the genitive to express "of work." Together, they literally mean "before the start of work."