The Highlights feature can be quite useful if you want to focus on one sentence at a time by highlighting the current sentence and fading out the rest of the text. Note that, as any other modus, sentence highlighting doesn’t modify the text itself but just it’s visual appearance within the editor.
To enable this feature, select Modus > Highlights.
In addition you can jump to the previous and to the next sentence, too, without having necessarily the Highlights modus enabled. When you use one of these two features, the blinking cursor moves automatically to the end of the previous/next sentence. When jumping to the end of the next sentence, the blinking cursor actually moves the the end of the current sentence; only if it already is at the end of the current sentence it moves to the end of the next one.
Shortcuts for these two commands are CMD-LEFTARROW and respectively CMD-RIGHTARROW.
How do sentence ranges work? The range of a sentence is found by looking for the previous and the next stop for a given location in the text. We refer to „stop“ as a dot („.“, „?“, „!“), a newline character or the bounds of the text. Once the right and left stops have been found, it’s easy to find the start and the end of the sentence: the non-whitespace character following the first whitespace after the stops is set to be the start/end of the sentence.
Just keep in mind that after the end of a sentence there should be some whitespace. This allows sentence boundaries to be detected properly and at the same time it’s a good writing habit.