Is it possible to spell-check multiple languages in Chrome?
Each time I check "Use this language for spell checking" in one language, it is unchecked in all the other languages...
This is being tracked in issue https://code.google.com/p/chromium/issues/detail?id=5102. You should "star" the issue to be notified of progress.
Currently there seems to be no way in doing this.
Now there is a way to store your preferred language on any host address and load it automatically, so you only have to set it for every website once.
Configure your base and additional languages and switch it on any host by clicking the icon, it will be stored and load the preferred language when you return the website, again. Beware, set the right languages you see at
chrome://settings/languages as there are plenty of sub languages based on the location (accent).
Happy spell checking.
This is now possible on the stock Chrome browser, as of ~October 2015 (after sitting seven years as an open issue). You just need to go to Settings > Languages > Language and Input Settings, and click the spell-check box for however many languages you want: