首先文章写的很好!
My dream house is a single house.
It has three storeys.
On the first floor there is a big living room,a medium-sized dining room,a kitchen and a bathroom.
On the second floor there are three bedrooms and a bathroom.
On the third floor there is a reading room,with collections of books and a bathroom.
Outside of the house,there is a swimming pool,because the sport I like best is swimming.
There is a garage,of course.I hope to keep the car in the garage.
And there is a very big garden,I hope to plant many flowers and trees in the garden.
This is my dream house.
表示某处有某物时要用there be,而 have/has/had则是用于人拥有.