If you're working with multiple languages in Chrome, it can be very helpful to have your spelling checked in those languages. Weblog Ghacks has a guide to installing other dictionaries.
When you install Chrome, a default language dictionary is installed along with it. Chrome will only offer spell checking for that default language -- unless you install other dictionaries separately. You can add additional languages to Chrome and set those languages to spell check whenever you like.
After you install the language packs and a few setting are tweaked you can right-click in any typing field within Chrome and select a different language to check your spelling with. Hit the link below for the step-by-step instructions.