What German and English language are both believed to be descended from which source?

Both German and English are believed to be descended from Proto-Germanic, a prehistoric language spoken by the Germanic peoples in the first millennium BCE.

Here's a simplified breakdown:

* Proto-Indo-European (PIE) was a language spoken around 4500-2500 BCE, which is the ancestor of many modern languages in Europe, Asia, and parts of the Middle East.

* Proto-Germanic emerged as a distinct branch of PIE, around 500 BCE.

* German and English (along with other Germanic languages like Dutch, Swedish, and Norwegian) developed from Proto-Germanic over time.

While Proto-Germanic doesn't exist anymore, linguists have reconstructed a significant amount of its vocabulary and grammar based on its descendants.