'wait, what was that?' feature

We're never going to get 100% perfect word timings, and some passages of text are just plain harder to read than others, often due to funky grammar and the like.

So when I've finished this new parsing/instructions functionality, I'm gonna come back here and remind myself to implement a button/keybinding which navigates backwards by sentences and reduces the target WPM by 100 or so until you get back to where you were originally.

Start by reviewing the parsing/instructions functionality mentioned in the issue, then locate the controls and sentence-navigation entry points it exposes. The feature is done when a button or keybinding moves backward by sentence and lowers the target WPM by about 100 until returning to the original position.

Written by the indexing model from the issue text.