MacVim IM INSERT MODE

Question

While using MacVim to edit markdown files, when I enter the insert (i) or append (a) mode and type the grave ` character to start or end a line of code, MacVim switches to IM INSERT MODE and sometimes just overwrites the grave ` character. What is this mode and how can I prevent MacVim from overwriting the grave ` character?

Answer 1

` is a dead key in your active input method (keyboard layout).

IM INSERT is MacVim letting you know that you are using a Mac OS X input method mode where your keystrokes will probably be given special interpretation.

You can manage the available input methods in the Input Sources tab of the Language & Text preference pane in the System Preferences application (i.e. the  > System Preferences… menu item). You will probably want to enable Show Input menu in menu bar at the bottom to make it easy to switch input methods (and enable the Keyboard Viewer where it is easy to see the dead keys (they are a different color)).