Use participial constructions instead:
2. A little boy sat on a suitcase and waited for his father.
3. We watched people who bought their tickets.
4. We saw a woman who was looking for her little boy.
5. We heard men who shouted at each other.
6. Mike's hair was rather long. (What is he to do?)
7. Mother needed a new dress. (What is she to do?)
8. At home I found a letter, which was written by my best friend.
9. When I saw the letter I quickly opened it.
10. Did you see the Prime Minister when he arrived?
A man came along the platform and called a porter.
A man came along the platform, calling a porter.
1. We stood and watched the trains.