Level A1
There is / There are
There is for one, there are for more than one.
There is a cat on the roof.
One cat, so: There is.
Forms
There is + one → There is a cat.— one thingThere are + more than one → There are two cats.— more than oneThere's = There is— short form
A common mistake
Wrong: There is two cats.
Right: There are two cats.
Two cats are more than one, so: are. We say: There are two cats.
More examples
There are three books on the table.
Three books: There are.
There is a park near my house.
One park: There is.