Modifying Form Validation Error Messages
When a visitor fills out the form on your page but their form entry doesn't validate, they'll see some errors, which look like this by default:
You can modify and customize the wording of these errors by adding a snippet of Javascript to your landing page. Here's the script:
To add it to your page, click Javascripts 
button in the bottom left of the Page Builder, and then paste the script in.
To customize your form validation error messages, amend the values after the = sign to whatever you'd like your new message to read.
Here's the result:
