Who walks two kilometers to his office every day?
or
Who does walk two kilometers to his office every day?
NOT A TEACHER
(1) As the moderator told us, it depends on the context.
(2) You might address a meeting of 100 employees and say:
We are conducting a survey of our employees who walk to work instead of driving.
I need to know who walks two kilometers to work every day. Please raise your hands.
(3) On the other hand, you might say this to your boss:
Someone told me that a few employees walk two kilometers to work. I have
already spoken with 90 of our 100 employees, and they all tell me they drive their cars
or take public transportation. I'm wondering who does [in fact] walk two kilometers
to work every day! Was I given the wrong information? This seems to be the case,
doesn't it!