The article about John Wycliffe on wikipedia runs:
[Wycliffe] completed his translation directly from the Vulgate into vernacular English in the year 1382, now known as the Wycliffe Bible. It is believed that he personally translated the Gospels of Matthew, Mark, Luke, and John; and it is possible he translated the entire New Testament, while his associates translated the Old Testament.
It’s certainly believed that Wycliffe did all this, but sadly, there’s no evidence for any of it. It’s generally accepted that the work known as ‘Wycliffe’s Bible’ was the work of other hands. There was a very wooden translation of the Old Testament done by a man called Nicholas of Hereford, and this was revised and added to by other hands, probably including someone called John Purvey.
There’s no doubt, having said all that, that Wycliffe was in favour of the Bible and other teaching being published in English; he is clearly the inspiration behind the work. Those involved were all disciples of Wycliffe. He may have played a role in planning and direction, but of his direct involvement there’s no evidence. It’s another of those facts that get handed down and never really questioned.
And, of course, it creates something of a problem for all those excellent people at Wycliffe Bible Translators – because the ‘Purvey Bible Translators’ doesn’t really work that well…