The King James Version, “and he went out, and followed him,” represents a fairly literal translation of the Greek, but it suggests that first Peter went out of the prison and then followed the angel. The meaning is “he followed him out” (Phillips, New English Bible) or, more explicitly, Peter followed him out of the prison.

It is not always easy to translate the expression real. In some languages one must employ some such form as “he did not know whether he was really going out of the prison, or whether he was simply imagining this,” “he did not know whether he was dreaming or whether this was actually happening,” or “he was not sure that he was going out of the prison; he thought he was seeing a vision.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .