We say "the suburbs are", not "the suburbs is". Being "suburbs" a plural noun, it takes a verb in the plural.

We say "the suburbs are", not "the suburbs is".

The suburbs are a great place to raise a family.

Being "suburbs" a plural noun, it takes a verb in the plural.

The suburbs of Chicago have become more attractive to college graduates.

What's the difference between a suburb and the suburbs? A suburb is a residential area or town near a large city but away from its center. In a broader sense, we use the expression "the suburbs" to speak about the residential outskirts of a city or town.

He's a kid from the suburbs.

I used to live in a suburb of Atlanta.

Plural nouns, like "suburbs", require a determiner or pronoun in the plural.

I like the suburbs. They are a great place to live.

Keep in mind that we use the proposition "in" before "suburbs" (not "on").

Living in the suburbs of Madrid is cheaper.

Follow the same strategy with the plural nouns "outskirts" and "surroundings".