Learn Finnish: Kokous oli viivästynyt, ja myöhemmin se oli peruuntunut. - The meeting had been delayed, and later it had been cancelled.

The pluperfect (had done something) is built using the past tense of the verb olla. Here we use oli because the subject (kokous) is a singular third-person noun. We then add the past active participle of the main verb, which ends in -nut or -nyt for a singular subject, giving us viivästynyt and peruuntunut.

The English translation says "had been delayed" and "had been cancelled". Why doesn't the Finnish sentence use the passive voice?

In Finnish, verbs ending in -ua or -yä, like viivästyä (to get delayed) and peruuntua (to get cancelled), describe an action that happens on its own or a change of state. Because the subject (kokous) is undergoing the change itself, Finnish uses the active voice, even though English naturally translates it with the passive "had been".

If peruuntunut means the meeting got cancelled on its own, how would I say that someone specifically cancelled it?

You would use the transitive base verb perua (to cancel). If you wanted to say "The manager had cancelled the meeting", you would say Päällikkö oli perunut kokouksen. The verb peruuntua is used when the meeting simply "falls through" or when who cancelled it isn't the focus.

Why does viivästynyt end in -nyt but peruuntunut ends in -nut?