Biblical Examples

There are interesting examples in the Bible that illustrate some of the issues relating to dialects and multilingualism.

Dialects:

Different dialects had fatal consequences in the story of "Shibboleth" in Judges 12:5-6. Here we see a regional dialect (specifically represented by pronunciation) being used to identify a person's native region.

Peter was also identified by his Galilean dialect in the court of the High Priest (Matthew 26:73). We are not told exactly what the identifying marks were, but his dialect gave away his origin.

Multilingualism:

Many people in the world use one language at home and another to conduct official business or relate to those outside their group. The story of the attack on Jerusalem at the time of Hezekiah (Isaiah 36) shows that this was the case for the Jewish officials at the time -- they spoke Hebrew within their group, but Aramaic to official outsiders. The Assyrian official intentionally chose to use the common language to communicate with everyone, even though the Jewish officials could (and wanted to) speak Aramaic : "“Please speak to us in Aramaic, for we understand it well. Don’t speak in Hebrew, for the people on the wall will hear.”"

When arrested in Jerusalem (Acts 21:37-22:2), Paul used his two languages to his advantage -- one language to insist on his rights and "power" to the Roman official, and the other to express his solidarity with the crowd.