I am trying to find all words in my file that are 4 characters long and start with a B or b and delete those words. I am trying to break down the regular expression into parts and build onto it as I get things working. So far, I am just trying to delete words starting with a B using this vi command: g/^B/dw, but I get a 'Not an editor command: dw' error. Could someone point me in the right direction? thanks.