The commands in a Vimscript file are executed in command mode by default. Therefore all non-command mode directives should be prefixed.

Hello World

When attempting to print something for debugging in vimscript, it is tempting to simply do the following.

echo "Hello World!"

However, in the context of a complex plugin, there are often many other things happening right after you attempt to print your message, so it is important to add sleep after your message so you can actually see it before it disappears.

echo "Hello World!"
sleep 5

Using Normal Mode Commands in Vimscript

Since a Vimscript file is a collection of Command mode actions, the user needs to specify that the desired actions should be executed in normal mode.

Therefore executing a normal mode command like i, a, d etc. in Vimscript is done by prepending the command with normal:

Going to the bottom of the file and selecting the last 5 rows:

normal GV5k

Here the G instructs vim to change the cursor position to the last row, the V to go to linewise visual mode , and the 5k to go 5 rows up.

Inserting your name at the end of the row:

normal ABoris

where the A puts the editor in insert mode at the end of the row and the rest is the text to insert.