After seeing lifehacker, I was inspired to add an adverb detector to TextMate’s markdown grammar, since that’s the format I use to write blog posts.

Far from being a couple of hours work, this was dead simple, and involved adding a couple of tiny bits to the grammar, here’s how to do it:

First, fire up TextMate’s Bundle Editor, press ⌃⌥⌘B. Then scroll to markdown, expand it, and find the Markdown Language grammar. This will be marked with a small grey L. Add the following to the repository section:

    adverb-detector = {
        name = 'invalid.adverb';
        match = '(?!\b(supply|apply|family|only|prolly|folly|sully|rally|waverly|reply|early|probably)\b)\b(\w+ly)\b';
	};

Now scroll to the section headed inline, and add:

    {	include = '#adverb-detector'; },

To the patterns part. Finally, check you have a rule called Invalid in your TextMate theme, with the scope selector invalid. This rule is used to highlight a multitude of sins, so it’s probably already in your theme. Mine looks like this: