What are examples of subject pronouns in a sentences?

Examples of subject pronouns in sentences:

When George got to 19th Street, he got off the train.

Gina made cookies for the class. She often bakes treats for class.

The tree broke in the storm and it hit the car.

We had a good time at the picnic.

They said it would rain today but it didn't.

Everyone who was on the bus got off at the mall. (Everyone is the subject of the sentence; who is the subject of the relative clause.)