## ways to get into insert/replace modes ##

i: duh
a: "append"; insert mode immediately after char under cursor
A: line append; insert mode at end of line
I: line insert; insert mode at beginning of line
cw: "change word"; delete from cursor to end of current word, then insert
r: replace char under cursor, then leave replace mode
R: replace mode and stay in replace mode

## copy & paste ##

copy (yank) current line to clipboard register:

copy several lines or a block of text to clipboard:
visually select the text you want, then 'y'

cut some text:
just delete it; every time you delete something, it automatically goes into the default
clipboard register.

paste the most recently yanked or deleted bit of text:
(note:  this leads to the mnemonic "xp" to transpose two letters
-- the x deletes, then p immediately pastes; "xp" just happens to read like

you copied some text, then deleted some other text, and you want to paste the
copied text, not the just-deleted text:

list what's in all the clipboard registers:
(to paste one, type the text before it, e.g. "4, then type p)

copy text to a register named 'x', because you're going to want it much later
after some other copying & pasting and you don't want it to scroll away:
if some text is selected: "xy
to grab the current line: "xyy
(note: this named register will persist pretty much forever, even after you
close and reopen vim. you can use other letters besides x.)

## split view ##

split the window horizontally:
(hint: to make the new piece of the split appear below by default, put
"splitbelow" in your .vimrc; stock configuration has it appear above, which
can be disorienting)

split the window vertically:
(hint: to make the new piece of the split appear to the right by default, put
"splitright" in your .vimrc; stock configuration has it appear on the left,
which can be disorienting)

move between splits:
   up: ctrl+w,k
 down: ctrl+w,j
 left: ctrl+w,h
right: ctrl+w,l

open a new file (can exist or not), and have it appear in a split view beside
the current one:
:vsplit newfilename.txt

close split part currently containing the cursor:

make the current part of a split view 9 lines taller,shorter,wider,thinner:
ctrl+w, 9+
ctrl+w, 9-
ctrl+w, 9>
ctrl+w, 9<

make the split parts equal size:
ctrl+w, =