1. She had been tired. I had played basketball.
2. She had finished writing letters. Her mother had arrived.
3 The child had cut his finger.
4. The rain had stopped. We had moved home.
5. He had decided to study French. He had left school.
6. Sam had worked hard.
7. The house had been build. The tornado had ruined it.
8. My brother had received an e-mail. He had written back.
9. I had bought a new dog. My old dog had died.
я не знаю во всех ли тебе предложениях нужно поставить время Past Perfect. Я поставила во всех. Просто ставишь глагол "had" и глагол в 3форме.
Мне кажется, что не все предложения нужно переделывать. Нужно переделывать только второе под паст перфект я думаю, но на всякий случай сделала все.