Here's a list of sentences with plural nouns for your edification:
The cats and dogs were playing in the park.
They had a ball, but not the idiomatic phrase of the ball.
The birds and fish swam in the lake.
They were having a fin-tastic time, but not without subject-verb agreement issues.
The children and women were playing in the sandbox.
They built a castle, but it was a bit of a mess.
Stay tuned for more examples of plural nouns in action!