#verb to exist to not exist

있다 - 있어요: To exist, to have
없다 - 없어요: To not exist, to not have

Example:
책이 있어요.
There is a book.
책이 없어요.
There isn’t a book.

This type of sentence can have two subjects:
One naming the possessor of the object.
The other naming the object possessed.
Example:
내가 연필 이있어요. 
I have a pencil.

However, it is more usual for the possessor to be expressed as a topic and the nouns possessed as a subject.
Example:
우리는 개가 없아요. 
We don’t have a dog.

Info from Elementary Korean Second Edition