What language did Saint Luke speak?

Saint Luke, the author of the Gospel of Luke and the Acts of the Apostles, was a Greek physician. Therefore, he likely spoke Greek.

While he was born in Antioch, which was a predominantly Aramaic-speaking city, he lived and traveled throughout the Roman Empire, where Greek was the lingua franca. He was also a companion of the Apostle Paul, who spoke Greek.

It's also worth noting that Luke wrote his Gospel and Acts in Koine Greek, the common language of the Hellenistic world at the time.