Editing

Say what you mean, then say what to do with it. Because the selection always comes first, you can see exactly what an edit will touch before it happens — and the same handful of action keys work on a character, a word, a block, or forty places at once.

Inserting text

Key	Where insertion begins
i	Before the selection
a	After the selection
I	First non-blank character on line
A	End of line
o	New line below
O	New line above

Press Esc or Ctrl+c to return to Normal mode. Ctrl+w deletes the word before the cursor while you type.

Deleting and changing text

Key	Effect
d	Delete selection (pushed onto the kill ring)
c	Delete selection content and enter Insert mode (one undo group). A trailing newline is kept — c on a line rewrites its content without removing the line itself.

Use x to select the current line first if you want a line-wise delete (x then d).

See Copy & Paste for what the kill ring is and how to paste from it.

c keeps the selection on the text you changed: leaving Insert mode selects your replacement instead of leaving a plain cursor, so you can immediately act on it again — delete it, surround it, search for it. Pressing Esc without typing anything leaves the cursor where the change began. Disable this with the select-changed-text option (see Configuration).

Whichever way you entered Insert mode, m i i recovers what you last typed after Esc — see Text objects.

Replacing text

Key	Effect
r + char	Replace every selected character with the typed character

Line endings inside the selection are left alone, so replacing across several lines won't collapse them into one. On a single character, r is delimiter-aware: replacing one half of a bracket or quote pair updates its partner too.

Enter and Tab count as the typed character, replacing with a newline or tab.

Changing case

Key	Effect
g u	Lowercase the selection
g U	Uppercase the selection
g C	Capitalize the selection

Lines and alignment

Key	Effect
J	Join the selected lines into one
&	Align selections into a column

J replaces each line break with a single space and drops the next line's indentation, so joining wrapped code or prose doesn't leave a gap in the middle. When the next line is empty or only whitespace, the lines are joined with no space at all. Joining several lines at once leaves one cursor on each inserted space, ready to act on.

& lines up your selections using the primary selection's line as the starting point. Spaces are inserted at the left edge of each selection to reach that column, and if some other line needs more room, the column widens for everybody — which means the primary selection can shift right too. Multi-line selections are left alone. Where a selection sits too far right already, the run of spaces or tabs immediately to its left is squeezed down (never below one).

You can align to the left or the right depending on which end of the selection is the anchor; Ctrl+e swaps anchor and head. See Selections.

Undo and redo

Key	Effect
u	Undo (accepts a count — 5u undoes five steps)
U / Ctrl+r	Redo

Undo history is a tree rather than a straight line, so redoing after new edits follows the most recent branch. The history lives in memory only and starts fresh each time you open a file.

Repeat

Key	Effect
.	Repeat the last editing command

Dot-repeat replays the most recent insert session or editing command — delete, change, paste and so on, but not y. Give it a count to override the original: if 3w set up the first change, 5. repeats it over five words instead.

Macros

Macros record and replay sequences of keys and are stored in registers. Register q is the default.

Key	Effect
Q Q or Q q	Start recording into the default register q
Q <0-9>	Start recording into a numbered register
Q (while recording)	Stop recording
q q	Replay register q
q <0-9>	Replay a numbered register
<count> q q	Replay register q <count> times

Recording is ignored in read-only buffers, and while a macro is already recording or replaying — so a macro can't record itself or nest.

Numeric count

Prefix a command with digits to repeat it. The first digit must be 1–9; 0 counts only once a count is already under way. So 12w moves forward 12 words and 10j moves down 10 lines.

Example	Effect
3w	Move forward 3 words
5j	Move down 5 lines
12w	Move forward 12 words
10j	Move down 10 lines

0 on its own does nothing by default — g h goes to the start of the line. If you want vim's 0, the core:vim-keybind plugin binds it (see Core Plugins).

Surround

HUME's surround commands select or wrap delimiter pairs using the m prefix — see Selections for the full list of m i/m a text objects.

Key	Effect
m s + char	Select the surrounding delimiter pair (both ends)
m w + char	Wrap each selection with a delimiter pair

To delete or replace a pair, select it with m s and then act: m s ( then d deletes the parentheses, r replaces them.

Cursor inside, press m s (
call(one, two)

Press d
callone, two

...or press r [ instead
call[one, two]

Helix-style surround (bundled plugin)

If you prefer Helix's dedicated surround keys, a bundled plugin provides them:

Key	Effect
m s + char	Wrap (add surround)
m d + char	Delete the surrounding pair
m r + char + new	Replace the surrounding pair with a new delimiter

Note that this moves wrapping onto m s: it takes over the default m s (select the pair) and removes m w.

(load-plugin "core:helix-surround")