You should turn it into an assertion because then with your essay or whatever you're using to back it up, you can affirm that your thesis statement is true/correct or w/e
The interview is like an informal and formal one. A lot is expected to an interview. It doesn't really have to be formal or not because everything is subjective. It is informal compared to an essay. It is formal compared to a speech.
It is false that the attitude of the person making a complaint never influences the filing of that complaint. It may happen that it does influence it.
Okay, did you have a conversation with one of the higher people in your school? If you're uncomfortable report it to the office.
