I have to write a report with 3 other people about a project work.
We split it up in different parts. First things went slowly and but a week later one group member have written a very good complete introduction, even that he was struggling heavily with other parts. As an information the report isnt in his native language.
After a while I noticed the whole introduction is copied from 2 other sources. Hardly a word was changed. In a first try I told him to write down his sources for the information but he just said something like: there is no source everybody knows that so he does too.
How can I tell him to rewrite his part without being to harsh but still being clear he has to do it?