Використовуйте past perfect simple with action verbs to emphasise completion of event. We use the past perfect continuous to show that event or action in the past still continuing. Будівнички були поставлені до шолома біля будинку.
Ці дві tenses є both used to talk o things that happened in the past. However we use past perfect to talk about something that happened before another action in the past, Котрий is usually expressed by the past simple. Для прикладу: "Я маю на увазі eaten my dinner when he called."