put the verb into the Present Perfect. надо подставить 4формы He (take) his exam for half an hour already.They (play volleyball) They (play volleyball) since 2 o'clock.

he has been taking his exam for half an hour already.they have been playing volleyball since 2 o'clock.He has taken, He has been taking, He will have been taking, He had taken.They have played, They have been playing, They will have been taking, they had taken kajetsya tak