I'm far from any authority on this, but the basic word for "word" in Hebrew is debar, and my understanding is that it is compounded with other words to add extra meanings. For instance, there is an expression for a word that comes into completeness as it is being spoken, sort of like what happened when Jesus said at Capernaum, "Today, this scripture has been fullfiled in your hearing". I have been looking for that expression for years, without success.
I'm also no authority on Paul, and while I would expect him to be fully fluent in the Hebrew, having studied under Gamaliel, I would be very surprised if he weren't also fluent in Greek, which I believe was the
lingua franca of the day. John 19.20 has the inscription over Jesus' head in Aramaic, Latin and Greek. Aramaic was for the uneducated Jews, Latin for Roman law, and Greek for general consumption, I believe.
Ah yes, Acts has Paul speaking Greek:
And when he came to the steps, he was actually carried by the soldiers because of the violence of the crowd,
for the mob of the people followed, crying out, “Away with him!”
As Paul was about to be brought into the barracks, he said to the tribune, “May I say something to you?” And he said, “You know Greek?
Then you are not the Egyptian, who recently stirred up a revolt and led the four thousand men of the Assassins out into the wilderness?”
Paul replied, “I am a Jew, from Tarsus in Cilicia, a citizen of no obscure city. I beg you, permit me to speak to the people.”
And when he had given him permission, Paul, standing on the steps, motioned with his hand to the people. And when there was a great hush, he addressed them in the Hebrew language, saying: -Acts 21:35-40
Paul's need for knowing Greek would be compelling, considering the life and death nature of the volatility of his excursions into Greece, Macadonia, Pisidia, Galatia, etc. And I see no mention of a translator on his journeys.