Official Permission
Paul was in chains (Acts 21:33). Arrested by the Roman soldiers in order to quell a riot and establish their authority, Paul was carried above the heads of the crowd up the steps of the military barracks (Acts 21:35). But before they entered the building, and the heavy gates slammed shut behind them, Paul spoke respectfully to the commander asking permission to speak to him. The officer was surprised to hear the apostle speaking in educated Greek. He wrongly assumed that Paul was an Egyptian terrorist leader; such people certainly did not speak Greek.
So Paul then explained that he was a Jew from Tarsus, in what is now south eastern Turkey near the present town of Adana. Tarsus was a cultural and academic centre under Roman rule but exempted from paying Roman taxes. All who were born there, like Paul, automatically became full Roman citizens. As such, they had special rights in all parts of the Roman Empire, and were legally protected from punishment or ill treatment without a fair public trial (Acts 16:37-39).
So Paul asked for permission to address the crowd. Using the steps as his pulpit, he changed his language to Aramaic, which most of the crowd would understand. As he did so, under the commander's authority, the crowd fell silent to listen to him. It was a sort of public pre-trial. He addressed his religious accusers as brothers (identifying with them as a Jew) and fathers (recognising the presence of high ranking priests in the crowd). Then Paul gave his personal testimony. He was always looking for a way to present the Lord Jesus as Saviour and Lord and what more authentic way than to describe how he first encountered Jesus.
The gospel of God's grace should be presented graciously (Luke 4:22). There is much wisdom in asking if you can speak about Jesus, or describe your experience of Him. If the gospel is to be received, the listener should first agree to hearing it. Ask, "Can I tell you how I found Jesus / became a follower of Jesus Christ?"; "I would like to tell you how I first met Jesus, and what a difference He has made in my life; would you like to hear?" For many believers, it is also helpful to have a clear description of the gospel to share; try using CrossCheck (www.crosscheck.org.uk). It never hurts to ask permission. Sometimes you will be refused; but when they agree to listen that is a big first step towards them wanting to follow Jesus too.