Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
By default, the pop-down floating tool menu - where you select the pen or erase tools - lives on the left side of the screen.
Source: https://www.pocket-lint.com/amazon-kindle-scribe-tips-and-tricks/