Set two languages simultaneously for the stock keyboard? I want to have both english and german prediction and auto correction at the same time for the stock keyboard (Jelly Bean here).

My use case:
Multi-tasking between english and german domains on my tablet where I both need the keyboard (e.g. Google Talk with my german friends and editing/answering questions on Android Enthusiasts in english). Problem: I don't want to switch off prediction/auto-correction nor do I want to switch to an alternative keyboard. At the moment I have to manually switch between en/de keyboards when I switch tasks (from Google Talk to the browser and back). This is annoying. I don't mind the keyboard layout (QUERTZ or QUERTY) but would prefer the english one.

How can I have simultaneous multi language prediction/auto-correction in the stock keyboard?
The stock keyboard in Jelly Bean (4.1 or 4.2) does not support multiple languages simultaneously. However, SwiftKey, a third party keyboard, supports advanced predictions with up to three languages simultaneously.

SwiftKey Official Website
SwiftKey on Google Play

Note that SwiftKey is a paid app. You can find the non-trial versions of the application in the Play Store. If you are looking for Swype-like functionality, note that an upcoming version of SwiftKey also includes it.