rumus when while di past perfect

kita biasanya gak pakai when while di past perfect
di past perfect kita makenya after atau before biasanya.
when while biasanya di past continuous.

past perfect rumusnya
Subject + had + Verb3 + O

when itu dipake di past continuous kl tense kalimat yg di belakangnya digabung sm past simple.
while itu dipake di past continuous kl tense di belakangnya past continuous