vi file
:set nu

a append new text arter the cursor
i insert new text befor the cursor
u undo
. repeat

h move the cursor left one characther
j move the cursor up one line
k move the cursor up one line
l move the cursor right one characther

ctrl + F
ctrl + B
ctrl + D
ctrl + U

dd

:read <filename>  => ctrl + i

/<pattern>        => ctrl + s
?<pattern>        => ctrl + r
n once again forward
N backword

1G
G                 => esc + <
p,P               => ctrl + y
x                 => ctrl + d
D                 => ctrl + k
0                 => ctrl + a
$                 => ctrl + e


o open a new line below the line the cursor is on  
and start entering text

/ text search for the swtring "text in the file,
Ctrl-A
Ctrl-B