A classmate invited the teacher to be a judge on behalf of the whole class.

First of all, make a basic self-introduction to the teacher, explain when, where and what competition will be held, and explain that you are the person in charge of this competition or specially invited by xxx to be the judge of this competition. Then introduce the significance and characteristics of this competition, and highlight the places that can attract him and the degree of attention. Then explain the reasons for asking him to be a judge, such as strong professionalism, rich experience, the same interests, and being deeply loved by classmates and teachers ... Finally, invite him to be a judge again and ask him if he can spare time to participate in this competition. Don't use "do you have time" when asking the time, it's better to use "can you spare the time?"

I wish you a successful invitation!