Here's why:
* Akkadian was the language of administration and scholarship: It was used in government, law, literature, and science.
* Chaldeans were part of Mesopotamian culture: They were a group of people who lived in southern Mesopotamia and played a significant role in Babylonian culture.
* Chaldeans used Akkadian for their own literature and records: While they had their own dialects, they primarily used Akkadian for writing.
Therefore, Akkadian was the main language studied by the Chaldeans, as it was the foundation of their intellectual and cultural life.