comment multiple lines in vim

1. keep the cursor on the first letter of first line to comment


2. in command mode, press ctrl + v


3. move cursor down until last line to comment


4. press I (you may not see vim going to insert mode, don't worry, you will see cursor moving to first line)


5. press # (you may not see # inserted yet, don't worry)


6. press Escape ( you should see lines commented out, otherwise, press escape two times)