en_tn/gen/06/04.md

giants

very large people

This happened when

This refers to the presence of the giants. It can be translated as "This happened because."

sons of God

Translate this as you did in Genesis 6:1.

These were the mighty men of old

"These giants were the mighty men who lived long ago" or "These children were the powerful fighters who lived long ago."

men of renown

"famous men"