"How many universities are there in Finland?"
Translation:Montako yliopistoa Suomessa on?
I don't really agree with Annika's analysis of the grammar here. This sentence doesn't have an agent, but it does have a subject. Even native English speakers generally can't explain how an agent and subject are different, as they're quite often the same thing.
The agent is determined semantically; it's who is performing the action. No one's performing any action here. The subject is determined by syntax and case, and it's the focus of the sentence.
I'd say 'yliopistoa', universities, is the subject of this sentence. Most of the time subjects are in the nominative, but sometimes they're in the partitive, like here.
'On' is a verb in the active voice. The passive form of that verb would be 'ollaan', which isn't in this sentence.
There is however a zero person construction, which has no stated subject and uses the third person active singular form of the verb, like 'on'. But I believe that in such constructions, the subject is either understood clearly from context (usually I or you), or the sentence is stating a general truth with a general subject. Like 'yöllä nukkuu', 'one sleeps at night'.
But I can't see how 'Montako yliopistoa Suomessa on?' would make any sense analyzed with a null subject. 'How many universities are you in Finland?' 'How many univerisities is one in Finland?'