It should also be noted that "which" quite often translates to "kumpi" instead. "Mikä" and its other inflected forms are used when the number of options have not been specified, and "kumpi" is used when the numbers of options have been limited to two options. Similarly to "mikä", "what" is used when the number of options have not been specified, but the crucial difference to note between "which" and "kumpi" is that while "which" is also used when dealing with a specific set of options, there may be more than just two specific options. "Which" is often used when there are just two specific options but sometimes there are more, so it depends on the context whether "kumpi" should be used in situations when "which" would be used in English. "Kumpi" always translates to "which", but "which" doesn't always translate to "kumpi".