Does the iPhone 11 save words or phrases I use often? Can I add or delete words to that collection?

Thank you for posting here in Apple Support Communities, idahoseewald.

We understand that you're wanting to know if the words or phrases that you regularly use on your iPhone are stored, and that you would like to have access to them. Those are some excellent questions, and we'd be happy to help provide you the information you'll need. The iOS software does remember words and phrases that you normally use in a feature called "predictive text". For more information, please check out: Use predictive text on iPhone

There's no way of going into predictive text to manage your words and/or phrases, the only option would to turn that feature on/off. However, there is a "text replacement" feature that you can use to add/remove text replacements. To learn more, please check out the "Set up text replacement" section here: How to use Auto-Correction and predictive text on your iPhone, iPad, or iPod touch

Let us know if you have any questions or concerns.

Cheers!