If Genesis is meant to be read literally, this is a fun thought: Eber, great-grandson of Shem, son of Noah, refused to help with the Tower of Babel, so the Hebrew language didn’t get confused during God’s action on humanity’s languages. Therefore, Hebrew is the same language Adam spoke.
It doesn’t have to be true. But it’s fun!
From the Wikipedia article on the word/name “Eber:”
The 13th-century Muslim historian Abu al-Fida relates a story noting that the patriarch Eber, the great-grandson of Shem, refused to help with the building of the Tower of Babel. As a result, his language was not confused when the tower was abandoned. He and his family alone retained the original Adamic language, which he identified as Hebrew, a language named after ĘżEber.