Learn Finnish: Kokous perutaan viidentenätoista, mikä on pettymys. - The meeting is cancelled on the 15th, which is a disappointment.

The word perutaan is the passive present tense of the verb perua (to cancel). In Finnish, the passive is used when the person doing the action is unknown or not important to the sentence. It translates as 'is cancelled' because we are focusing on the meeting itself, not on who cancelled it.

How does the word viidentenätoista mean 'on the 15th'?

To express that something happens on a certain day, Finnish uses the essive case, which adds a -na or -nä ending. The basic ordinal number for 15th is viidestoista. When you put it in the essive case, the first part inflects into viidentenä, but the -toista suffix (which works like the English '-teen') stays exactly the same.

Why use mikä here instead of the relative pronoun joka?

This is a key rule for connecting sentences! You use joka when the word 'which' refers back to one specific noun. However, when 'which' refers back to an entire previous sentence or situation (in this case, the whole fact that the meeting is cancelled), you must use mikä.

How is the word pettymys formed?