1. She *had been studying* for three hours before the exam started. (Dica: ação contínua antes de outra ação no passado)
2. They *had been playing* football all afternoon when it began to rain. (Dica: verbo no gerúndio após “had been”)
3. I *had been waiting* for the bus for 20 minutes before it finally arrived. (Dica: ação contínua no passado até um ponto específico)
4. He *had been working* at that company for ten years before he resigned. (Dica: verbo de trabalho no gerúndio após “had been”)
5. We *had been living* in Sofia before we moved to Plovdiv. (Dica: ação contínua no passado antes de mudar)
6. The kids *had been watching* TV when their parents came home. (Dica: atividade contínua antes da chegada dos pais)
7. You *had been driving* for hours when you finally stopped to rest. (Dica: verbo no gerúndio após “had been” para uma ação contínua)
8. She *had been cooking* dinner before the guests arrived. (Dica: ação em progresso no passado antes da chegada)
9. They *had been discussing* the project for weeks before the meeting. (Dica: ação contínua antes de um evento específico)
10. I *had been reading* that book for days before I finished it. (Dica: verbo de leitura no gerúndio após “had been”)

1. He *had been practicing* the piano for hours before the concert. (Dica: ação contínua anterior a outro evento)
2. We *had been traveling* all night when we reached the city. (Dica: verbo no gerúndio após “had been” para indicar duração)
3. She *had been cleaning* the house before the guests arrived. (Dica: ação em progresso no passado)
4. They *had been arguing* about the problem for a long time. (Dica: ação contínua no passado)
5. I *had been thinking* about the solution before you called me. (Dica: verbo mental no gerúndio após “had been”)
6. The teacher *had been explaining* the lesson before the bell rang. (Dica: ação contínua antes de um evento)
7. You *had been studying* all night before the exam day. (Dica: verbo no gerúndio após “had been” para ação contínua)
8. She *had been jogging* every morning before she got injured. (Dica: ação habitual contínua no passado)
9. We *had been waiting* for the train when it was canceled. (Dica: ação contínua interrompida por outro evento)
10. They *had been building* the house for months before it was completed. (Dica: ação contínua antes da conclusão)