Mark and region

The transient-mark-mode highlights the region between the point and the active mark, which resembles the selection in other text editors. To deactivate the active mark, type C-g. To mark a position for future reference, type C-SPC C-SPC.

Pop mark repeatedly with C-u C-SPC C-SPC....

(setopt set-mark-command-repeat-pop t)

Note: M-k kills not just sentences but also “text blobs” that “look like” sentences, such as code or result blocks in the Org Mode.

To see line numbers temporarily, type M-g M-g. To see them permanently, type M-x display-line-numbers-mode. To see them permanently everywhere, such as when pair programming remotely, type M-x global-display-line-numbers-mode.