0 used especially in questions when asking about which person owns or is responsible for something: --
1 used for adding information about a person or thing just mentioned: --
Cohen, whose short film won awards, was chosen to direct the movie .
There was a picture in the paper of a man whose leg had been blown off.
They meet in an old house, whose basement has been converted into a chapel.
Fraud detectives are investigating the company, three of whose senior executives have already been arrested.
2 used to ask which person owns or is responsible for something, or to say who is responsible for something: --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Можем да го завършим стъпка по стъпка, колкото и дълъг да е пътят и не може да бъде завършен, колкото и кратък да е пътят, ако дори не маркирате отпечатъка си.