. Правильно или не правильно составлено предложение?
1. I didn't know who she was. I'd never seen her before.
2. We weren't hungry. We'd just had lunch.
3. The house was dirty. They have not cleaned it for weeks.
4. He has worked at the university for thirty years before he retired.
5. Have he written a letter by 5 o'clock on Saturday?