Here's a breakdown of the factors:
* Upper German: This is a major branch of the German language family, characterized by certain grammatical features like the use of the "umlaut" and the "ich-form" (e.g., "ich habe" instead of "i hab").
* Central German: Within Upper German, Central German dialects are spoken in the central part of Germany. These dialects are generally considered more "conservative" and closer to the original High German than other Upper German dialects.
* Berlin dialect: The specific dialect that became the foundation for Standard German was the one spoken in Berlin. This was due to Berlin's increasing political and cultural influence during the 18th and 19th centuries.
It's important to note that Standard German isn't just a direct copy of any single dialect. It evolved through a process of standardization, borrowing elements from different dialects and using a consistent, formalized system of grammar and spelling.
Therefore, while it's based on a central German dialect from the Berlin area, Standard German is a constructed language rather than a purely natural dialect.