xerraire Anglais:

Penny is a chatterbox, but she still makes a wonderful friend.

Young John is a real chatterbox.

Sven was so verbose that his friends resorted to calling him a chatterbox.

She is a chatterbox.

She's such a chatterbox. She's on the phone for hours.

Your sister's a real chatterbox!

You’re such a chatterbox. Don’t you ever stop talking?

Vanessa is the biggest chatterbox in our class.

She is, in brief, a chatterbox.