In addition to direct questions, replicas are allowed: if, while listening to the report, you had an idea that you think might push the speaker to some interesting conclusions, do not hesitate to voice it.
By the way, questions are asked and the thoughts that have come to mind are voiced after the report, and not during it, and to the speaker, not the neighbor.
Be benevolent and correct. If the discussion gave the speaker some new thoughts, somehow contributed to his further scientific development, then the conference was not in vain for him. And it’s always nice.
Only a loser makes one report twice at different conferences. Twice one report can not be done. And three times too it is impossible. Yes, yes, and four times. Beginning authors who have written only one text, approved by the supervisor, for some reason forget about this rule of the scientific community and begin to send their theses to all possible conferences. However, students are usually forgiven, but in the list of publications 3 articles with the same title and almost the same volume are immediately shown to colleagues: you are dealing with a loser who forgets that the number of scientific publications must be supported by their quality.
In addition, in case the organizing committee finds out about duplicate articles before publication, it has every right to withdraw the work.
However, different reports can be made on the same topic – but isn’t it boring to write about the same thing two times in different words, strictly observing that the texts do not coincide?
At most conferences, two reports from one author are not welcome, even if they are on different topics. The reason is simple: it is difficult to prepare and read a report well. If a third-year student immediately declares 2 or even 3 reports, the question immediately arises about their quality. Why make 2 bad reports if you can make 1 good?
A separate problem – co-authors. In philology, co-authorship is not particularly common. In rare work there are 2 co-authors, even less often there are works where there are more than two co-authors. If this, of course, is not a serious scientific monograph, but we are talking about theses.