I work with 3 languages, on each of m storyboards Xcode 8 created my storyboardName.strings (language) files and i changed all the strings to the correct languages inside the double quote. I also have my localizable.strings files created for when i programatically need to change labels / alert messages.
Everything done programatically works fine on the simulator / device
The stroryboard don't translate on the simulator / device but work when i do the preview side by side and chaneg the language