How do I set spelling and spelling highlight for markdown files?

Question

When I do this:

:set spell spelllang=en_us
:hi SpellBad cterm=underline

It underlines the spell on markdown. I just need this auto command on markdown files.

If I put these commands in my .vimrc, and reopen a new vim with a README.md it doesn't underline the misspelled word.

How do I automatically underline bad spells on .md files. I use gruvbox colorscheme if that's any relevant. But I want a simple generic answer to apply to everything.

Answer 1

You could try putting it in an ftplugin; putting the command in ~/.vim/after/ftplugin/markdown.vim will define your highlight group after the color scheme is loaded on startup.

However, this may break when changing color schemes because color schemes will typically call :highlight clear to clear any previously defined highlight groups before defining their own. This can cause user highlight groups defined in .vimrc to be overridden.

To remedy this, you can create an autocommand that will execute a command every time a color scheme is loaded, but you'll need to check the filetype of the current buffer.

So, replace

set spelllang=en_us
hi SpellBad cterm=underline

in your .vimrc with

augroup UnderlineSpell
    autocmd!
    autocmd ColorScheme * if &ft ==? 'markdown' 
                          \| highlight SpellBad cterm=underline
                          \| set spelllang=en_us
                       \| endif
augroup END

It's important to wrap the autocommand in an augroup to prevent defining the autocommand more than once (if you were to change color schemes, for example). autocmd! is used to clear any existing autocommands defined for the current augroup.

There's also a very informative GitHub gist about overriding color schemes in this way that would be a good read.

---

Also see the following help pages:

• vim startup

  • :h vimfiles
  • :h after-directory

• autocommands

  • :h :autocmd
  • :h autocommand-events
  • :h ColorScheme
  • :h :augroup

• highlight and spelling

  • :h :highlight
  • :h 'spelllang'