Can you say are affluent in English?

It's not grammatically correct to say "are affluent" on its own. You need a subject for the verb "are." Here are some correct ways to use the word "affluent":

* They are affluent.

* The neighborhood is affluent.

* We are an affluent family.

* She is affluent.

"Affluent" means wealthy or prosperous, so you need to specify who or what is affluent.