Keyboard autofill: how to customize dictionary

When I use my Samsung Galaxy S10 keyboard to type an email or whatever, it will prompt me with suggestions. If I start typing "Res," it might offer Rest, Resume, & Respond above the virtual keyboard, so I can just touch one of the words rather than typing the whole word out.

Can I customize this? If I happen to have a friend named "Stephanie," can I set it up so that whenever I type in "Ste," it will include "Stephanie" among those suggestions? And conversely, if it offers up weird words I never use, can I remove them from the "dictionary" so they're no longer included among the suggestions?

Thanks!

Managed to solve it?

"Thanks for the detailed information. I often mistakenly add a word to the dictionary in the predictive text input and have to delete it often. I am going into Settings > Language and Keyboard. Press HTC ""Sense Input"" > Private Dictionary. I select the words you want to delete and press Delete.
I want to share my project, and I'm doing German-language websites about cars right now. I had to buy a German dictionary on Amazon, and I realized that it is quite clever. https://www.amazon.com/German-Freque.../dp/9492637308 I liked the fact that some words are used more often than others, so it is more valuable to know them. That's the whole secret to mastering a language quickly - learn the right vocabulary.*"