Saint Lawrence of Brindisi was the greatest linguist of his day. He could read, write, and speak Italian, Latin, Hebrew, Greek, German, Bohemian, Spanish and French.
Here's my favorite story about him. He was preaching somewhere and was being heckled by a Protestant minister about a Catholic doctrine not being found in the Bible. Saint Lawrence took his Greek New Testament and threw it at the man and said, "Read this!"
His knowledge of Hebrew was so thorough that the rabbis were convinced that he had once been a Jew who had converted to Christianity.