помогите пожалуйста что надо сделать и сделайте пж СРОЧНО!!​

1 I saw Helen yesterday,she hadn't changed a bit.

2 Mum gave me a sandwich to eat,but I had had breakfast.

3 We wanted to go to the country by car,but our car had broken down.

4 I was going to do the flat ,but my sister had already cleaned the flat.

5 When I came home and wanted to help my mum,she had already cooked dinner.