The post you are reporting:
Lesley, the four versions of the Gospel, written by Mark, Matthew, Luke and John, were indeed written in Greek, because all four spoke Greek. Many Jews in those days spoke Greek, especially if they were living in the Diaspora in Greek-speaking regions.
Similarly, Jews in the Diaspora living in other regions spoke the language of the land they lived in; however, Jews usually knew biblical Hebrew too.
The Jews living in Judea and Galilee spoke Aramaic, as did the Jews in Syria, Phoenicia and the Euphrates.
Aramaic is closely related to Hebrew.
The authors of the four gospels are all Apostles, and they lived in the first century.
Of these, only John was one of the Twelve Disciples of Jesus.
The Evangelist Matthew bore the same name as the Disciple Matthew; it's unlikely they were the same man, as Matthew Evangelist made no mention in his gospel of having been a direct Disciple (one of the Twelve), whereas John did.
Furthermore, Evangelist Matthew's gospel is based on that of Mark, as is Luke's.
This Makes Mark, Matthew and Luke "Pietrine" Evangelists, meaning they each base their respective recount on the oral testimony to Jesus Son of God given by Peter the Apostle.
Matthew and Luke also included testimony given unto them by Mary Mother of Jesus.
If you're following my posts here carefully, which seems to be the case, then you may notice that Peter did not write a version of the Gospel, even though he was one of the Twelve Disciples of Jesus.
This is the reason why Peter needed a successor, someone who would put his words and testimony of Jesus into writing for all time. This person was Mark the Evangelist.
Without Mark and the other Evangelists, there would be no Church, and no memory of Jesus.
The Catholic Church, in excluding the Evangelists as St. Peter's successors, initiated a line of popes that was a mistake from the start. The popes are not St. Peter's successors! The three Synoptic Evangelists are, beginning with Mark.
St. John, being one of the original Twelve Disciples, and therefore equal to St. Peter in terms of Witness of Jesus Christ, has a Ministry of his own, hence his Gospel is not considered Synoptic, as it is not based on St. Peter's testimony, but on John's own testimony to Christ.