'f' puts the contents of your previous cursor movement into
FBUF. If that movement was a forward movement, it brings the
cursor back where it was. This allows for an efficient combi-
nation of movements and 'E'. For example, if you want to delete
the next word, you type 'w', then 'f', then check your FBUF to
be sure, then press 'E'.

'R' goes into replace mode at current cursor position.
Following keystrokes replace current character and advance
cursor. Press return to return to normal mode.