Years of research on the sources of the gospels of Matthew and Luke led long since to three conclusions which many of us still find valid, first, that both these authors used our gospel of Mark; second, that they both used another source, commonly called Q; third, that each also used a source unknown to the other, and these two sources have been named M and L respectively. But about the nature of Q, M and L there are plenty of unanswered questions - such as, were they single sources or does each name cover several sources which we cannot easily disentangle from one another? Were they written or oral? How accurately do Matthew and Luke, who abbreviate Mark, quote their other sources? The language of Q was Aramaic; was the same true of other sources?