Here is a great example of why translation involves interpretation, and why a “word-for-word” approach can often fail.
When Jesus’ parents finally find Jesus, he responds, “Didn’t you know I had to be (δεῖ εἶναί με) in my Father’s house (ἐν τοῖς τοῦ πατρός μου)? (NIV).
As you can see from the Greek, there is no word for “house,” and yet every modern translation supplies “house.” The KJV is alone in suggesting another interpretation. “I must be about my Father’s business?”