VimSpeak lets you control Vim with your voice using speech recognition. For instance, you can say “select three words” to type v3w or “change surrounding brackets to parens” to type cs]) or crazy things like “change occurrences of ‘foo’ into ‘bar’, globally, ignore case, confirm” to type :%s/foo/bar/gic. Of course in insert mode you may dictate whatever you like. To learn the grammar, have a look at the unit tests and the code (“use the source, Luke”). It’s quite declarative and easy to follow.