What is the simple subject in sentence cards are exchanged modern

The simple subject of the sentence "Cards are exchanged modern" is cards.

Here's why:

* Subject: The subject of a sentence is the person, place, thing, or idea that performs the action of the verb.

* Simple Subject: The simple subject is the main word or group of words that acts as the subject.

In this sentence, the verb is "are exchanged," and the thing being exchanged is "cards."