Questions & Answers about Har ni er dator?
Why does this sentence use er for "your" instead of din?
Since the subject is ni (the plural "you"), we have to use the plural form of "your". Din is used when talking to just one person (singular "you"), but er is used when talking to two or more people.
Why is the possessive pronoun er rather than ert or era?
Possessive pronouns must match the gender and number of the noun they describe. Dator (computer) is a singular en-word, so we use er. If we were talking about an ett-word, like äpple (apple), we would use ert. If we were talking about multiple computers, we would use era.
If ni is plural, why is dator singular?
It means the group of people being spoken to shares a single computer. If you were asking if they have their multiple computers, you would use the plural form for both the pronoun and the noun: era datorer.
How do we know this is a question just by looking at the word order?
In Swedish, you form a yes/no question simply by putting the verb first. By swapping the subject and verb from Ni har (You have) to Har ni (Do you have), it becomes a question. You don't need a helper word like "do".