1.2 — Insert Mode — Entering Text#

Insert mode is where you actually type text, just like in any other editor. But Vim gives you multiple ways to enter Insert mode, each optimized for different situations.

What is Insert Mode?#

Insert mode is the mode where keystrokes insert characters into the buffer. It’s the closest Vim gets to a “normal” text editor.

When you’re in Insert mode:

• -- INSERT -- appears at the bottom of the screen
• Characters you type appear in the document
• The cursor is typically a vertical line (depends on terminal)

Ways to Enter Insert Mode#

Vim provides many commands to enter Insert mode, each placing your cursor differently:

Basic Insert Commands#

Command	Action	Mnemonic
i	Insert before cursor	insert
a	Insert after cursor	append
I	Insert at beginning of line	Insert at start
A	Insert at end of line	Append to line

Opening New Lines#

Command	Action	Mnemonic
o	Open line below, enter Insert	open below
O	Open line above, enter Insert	Open above

Replacing Text#

Command	Action
s	Delete character, enter Insert (substitute)
S	Delete line, enter Insert (substitute line)
c{motion}	Delete motion, enter Insert (change)
C	Delete to end of line, enter Insert

Choosing the Right Entry Point#

The key to efficient Vim usage is choosing the right command to enter Insert mode.

Scenario: Add text at the end of a line#

Inefficient: $ then a
Efficient: A

Scenario: Add a new line of code below#

Inefficient: $ then a then Enter
Efficient: o

Scenario: Replace a word#

Inefficient: dw then i
Efficient: cw (or ciw for the whole word)

Scenario: Fix a typo in the middle of a word#

Efficient: Navigate to the character, press s, type the correction

Insert Mode Commands#

While in Insert mode, you have some special commands:

Navigation (Limited)#

Command	Action
Arrow keys	Move cursor
Ctrl-h	Delete character before cursor (backspace)
Ctrl-w	Delete word before cursor
Ctrl-u	Delete to start of line

Special Insertions#

Command	Action
Ctrl-r {reg}	Insert contents of register
Ctrl-r =	Insert result of expression
Ctrl-a	Insert previously inserted text
Ctrl-t	Indent current line
Ctrl-d	Unindent current line

Exiting Insert Mode#

Command	Action
Esc	Return to Normal mode
Ctrl-[	Return to Normal mode (same as Esc)
Ctrl-c	Return to Normal mode (may skip abbreviations)
Ctrl-o	Execute one Normal mode command, return to Insert

The Ctrl-o Trick#

Ctrl-o is incredibly useful. It lets you execute a single Normal mode command without leaving Insert mode.

Example: You’re typing and need to save:

1. Press Ctrl-o
2. Type :w and press Enter
3. You’re still in Insert mode!

Example: You’re typing and need to scroll:

1. Press Ctrl-o
2. Press Ctrl-d to scroll down
3. Continue typing

Insert Mode Best Practices#

Keep Insertions Atomic#

Each time you enter Insert mode, make a single logical change, then return to Normal mode. This:

• Makes undo more useful (undo one logical change, not individual characters)
• Makes the dot command more powerful
• Keeps your edit history clean

Bad: Enter Insert mode, type a paragraph, make corrections, type more
Good: Enter Insert mode, type a sentence, exit. Repeat.

Use the Right Entry Command#

Don’t navigate in Insert mode. Instead:

1. Exit to Normal mode
2. Navigate to the new location
3. Enter Insert mode with the appropriate command

Leverage Change Commands#

The c (change) operator combines deletion with entering Insert mode:

ci"     →  Change inside quotes
ciw     →  Change inner word
ci(     →  Change inside parentheses
ct,     →  Change until comma

Practice Exercises#

Exercise 1: Entry Points#

1. Create a file with several lines of text
2. Practice using i, a, I, A to insert text at different positions
3. Use o and O to add new lines

Exercise 2: The Change Operator#

1. Write a sentence: The quick brown fox
2. Position on “quick”, press cw, type “slow”
3. Position on “brown”, press ciw, type “red”
4. Notice the difference between cw and ciw

Exercise 3: Ctrl-o#

1. Enter Insert mode and start typing
2. Press Ctrl-o then 0 to jump to line start (still in Insert mode)
3. Press Ctrl-o then $ to jump to line end
4. Continue typing

Exercise 4: Substitute Commands#

1. Position cursor on a character
2. Press s and type a replacement
3. On a line, press S to replace the entire line

Common Insert Mode Patterns#

Adding to End of Multiple Lines#

1. Ctrl-v to enter Visual Block mode
2. Select the lines
3. $ to extend to end of each line
4. A to append
5. Type your text
6. Esc — text appears on all lines

Inserting the Same Text Multiple Times#

Use a count before entering Insert mode:

1. 3i — enter Insert mode with count 3
2. Type “hello ”
3. Esc — “hello hello hello ” appears

Summary#

Command	Action
i / a	Insert before/after cursor
I / A	Insert at start/end of line
o / O	Open line below/above
s / S	Substitute character/line
c{motion}	Change (delete + insert)
Esc	Return to Normal mode
Ctrl-o	Execute one Normal command

Remember: Insert mode is for inserting text. Everything else belongs in Normal mode.