1.We stay at the Grand Hotel. Ann recommended it to us.
We stay at the Grand Hotel which Ann recommened to us.
2.The man is a computer expert. You are talking to him.
You are talking to the man who is a computer expert.
3.The new stadium will be opened next month. It can hold 90,000 people.
The new stadium which can hold 90,000 people  will be opened next month.
4.I saw a gril. Her beauty took my breath away.
I saw a girl whose beauty took my breath away.