Questions & Answers about Они избрали Ивана губернатором.
Why is губернатором in the Instrumental case instead of the Accusative?
In Russian, verbs of appointing, electing, or considering (like избрать) require the new role or title to be in the Instrumental case. The person being elected takes the Accusative case (Ивана), while the position they are given takes the Instrumental.
Why does Ивана end in -а?
Ivan is the direct object receiving the action of the verb избрали, so it must be in the Accusative case. Because Иван is an animate masculine noun, its Accusative form is identical to its Genitive form, taking the -а ending.
What would it mean if I swapped the cases and said Они избрали губернатора Иваном?
Because of how Russian cases work, swapping them changes the meaning entirely. The Accusative marks the person being acted upon, and the Instrumental marks the new role. So, that sentence would bizarrely mean 'They elected the governor to be Ivan.'
What is the imperfective form of избрали, and could we use it here?
The imperfective is избирали (from избирать). You would use it to describe an ongoing or repeated process, like 'They were in the process of electing a governor.' However, since this sentence describes a single, successfully completed action with a result, the perfective избрали is the right choice.