In my opinion, I think WSDC participants can be allowed to speak their mother tongue.

Thank you to participate in this debate. Then, this is my turn and I reply. First, Mulitilingual Users like your wife can easily understand what debaters say and have few mistakes to interpret and show well what accent are contained in thier words and what their words mean. And, I can find some important situations when I watch the videos of the Championships, participants of debate in the Championships also correct their words sometimes and they have delay sometimes when they don't have an idea for a while what words are proper to express their arguments and logics by using their relatively short English. No matter how judges try to consider this situation, it can impact expression of debators and can be valued estimation by judges. If debators can be allowed to use thier mother tongue, they can have less mistakes than present situation. In the current situation, Guaranteeing participation of simultaneous interpreters can guarantee debaters more choice who are English is relatively short. In my suggestion, they can choose between relatively short English that can provoke their own mistakes and delay and thier skillful mother tongue that can provoke mistakes by simultaneous interpreters. I don't think simultaneous interpreters in the situation who are good in many language have far more mistakes and delay than debaters who use their short English. In addition, debaters and simultaneous interpreters can also have the time to practice together before the time of debate so they can minimize their mistakes and debaters who have short English can believe simultaneous interpreters because they will well show their words without serious mistake and distracting words from debaters. Second, I can't exactly understand 'English-only debates will give those less able to speak English an extra incentive to learn.' But anyway, I reply. Artificial intelligence that can be used to translate also develop constantly and that can be realized that the level is not less than humen in the near future, so this stream will also give those less able to speak English an extra incentive to learn and people can speak their own language with foreigners by using the intelligence. This assumption is based on the information of the book named 'THE SINGULARITY IS NEAR' written by Ray Kurzweil. So I think English-only debate in the international contest of debate will be outdated in the future international society and the Championships also need to prepare this situation. Should we still preserve English-only to be allowed in the Championships? In addition, understanding English-only debates are also study of English in my case. I think it is not so specially different to others who also have short English like me. Third, I admit English language has the ability to promote international understanding. But I don't agree that would not otherwise be possible. In your example, your friend and participants of meetings can use English at least the appropriate level in the meeting. But, If they also have the appropriate level of the Swiss and Turkish or they can be helped by well-trained simultaneous interpreters, do you really think other languages would not possible to promote international understanding? Of course English Users in the other worlds can be more hard to understand and access the outcomes of the meetings, but the Swiss and Iranians who are the interested parties but who have English relatively short can be more understand and access more easily the outcomes of the meeting so international understanding can be also improved in the aspects. In addition, when simultaneous interpreters be allowed to participate in the Championships, they can also translate English to their mother tongue and this situation can be also filmed to videos so non-English users around the world can also have no special obstacles to understand whole debate, and international understanding can be more improved more than English-only to be allowed in the Championships. Finally, I admit your argument in this paragraph is right. But If participants can be allowed to choose English or thier mother tongue, don't you think they can express their opinion more easily and freedon of speech can be more guaranteed than present situaion? No matter how participants from non-Englishspeaking countries English well and English is a so flexible language, I think their English cannot overcome thier mother language in the most cases. What do you think about it? My counterattacks are over. I'll wait your reply.