1) There is a garden 

2) Because his house has many reasons: the garden,....

3) It's an old house about 20 year old

4) Yes,it is

5) Have 5 rooms

1. There is a garden in front of the house.

( There is a garden in front of the house )

2. The owner likes his house for many reasons : the garden, the flowers in the summer, the fire in the winter, but the best thing is the view from his bedroom window.

( I love my house house for many reasons : the garden, the flowers in the summer, the fire in the winter, but the best thing is the view from my bedroom window )

3. It is about 20 years old.

( It is an old house, about 20 years old and it is not very large )

4. Yes, it is.

( Câu hỏi dùng his hoặc her thì đúng hơn và nếu như vậy thì câu trả lời là : No, it isn't. The best thing is the view from his/her bedroom window )

( ... But the best thing is the view from my bedroom window )

5. There are five rooms in the owner's house.

( two bedroom + a bathroom + a kitchen + a living room = 2 + 1 + 1 + 1 = 5 )