THERE IS & THERE ARE

There is is used for singular or non countable nouns: 

there is a car in the street - hay un coche en la calle

There are is used for plural nouns.

There are some cars in the street - Hay algunos coches en la calle

Here you have some exercises to practise:

Exercise 1

Exercise 2

Exercise 3

Exercise 4

Exercise5

Exercise 6

Exercise 7