Point 78 in the category of PAST is defined as: past perfect continuous in relative clauses to give background information. who|that|which had been _vvg 1 WHO HAD BEEN WORKING 1233 2 WHO HAD BEEN LIVING 1080 3 THAT HAD BEEN SITTING 642 4 THAT HAD BEEN GOING 481 5 WHO HAD BEEN WAITING 479 6 […]