Learn Finnish: Onko täällä seitsemäntoista vai kahdeksantoista ihmistä? - Are there seventeen or eighteen people here?

In Finnish, sentences that state what exists in a place always use the singular verb on (is), even if there are multiple things. When you add the question ending -ko, it becomes Onko (Is there / Are there).

Why does the sentence use vai to mean 'or' instead of tai?

Finnish has two different words for 'or'. You must use vai in questions when you expect the listener to pick exactly one of the options provided (seventeen or eighteen). You use tai in normal statements, or in questions where you aren't asking the listener to make a choice.

Why is the word for people (ihmistä) in the partitive singular case rather than a plural form?

In Finnish, any exact number greater than one requires the noun that follows it to be in the partitive singular case. Because of the numbers seitsemäntoista and kahdeksantoista, the base word ihminen (person) changes to its partitive form ihmistä.

Where does the ending -toista come from in the words seitsemäntoista and kahdeksantoista?