How do human achieve communication according to functionalists ?

Jehovah communicated with Adam in the garden of Eden, using human language. God likely did so in an ancient form of Hebrew. He later made his thoughts known to Hebrew-speaking Bible writers, such as Moses, Samuel, and David, and they expressed these thoughts in their own words and style. Besides recording direct statements from God, they told of his dealings with his people, including accounts of their faith and love as well as those that revealed their failings and unfaithfulness. All this information is of great value today.—Rom. 15:4.
As circumstances changed, God did not restrict his communication with humans to Hebrew. After the Babylonian exile, Aramaic became the everyday language of some of God’s people. Perhaps to indicate what was to come, Jehovah inspired the prophets Daniel and Jeremiah and the priest Ezra to record portions of their Bible books in Aramaic.—See the footnotes to Ezra 4:8; 7:12; Jeremiah 10:11; and Daniel 2:4.
Alexander the Great later conquered much of the ancient world, and common, or Koine, Greek became an international language. Many Jews began to speak that language, leading to the translation of the Hebrew Scriptures into Greek. This translation, thought to have been done by 72 translators, became known as the Septuagint. It was the first translation of the Bible and one of the most important. The work of so many translators resulted in varied translation styles, from literal to rather free. Nevertheless, the Septuagint was viewed as God’s Word by Greek-speaking Jews and later by Christians.
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