The current subtitle is split into two separate subtitles. The time code (if any) is automatically recalculated for each new subtitle in conformity with its length.
If the original subtitle is split in the middle of a sentence a dash will be put after the first part of the split and before the second, if the Setup/preferences/toggle settings/Generate dash characters when splitting a text option is ticked.
If the original subtitle is italicized, both new subtitles will be, too.
Alt+S
See also: