For disrupting class
Dear Ma’am/Sir, I am sorry for disrupting the lesson and making it harder for you and the class to focus. My behaviour was disrespectful. I will be more responsible during class from now on.
For rude behaviour
I sincerely apologise for the way I spoke to you. Even though I was upset, I should have communicated respectfully. I understand that my tone was inappropriate.
For missing work
I am sorry for not completing the work on time and for not communicating earlier. I understand that I was responsible for the deadline, and I have corrected the pending work.
For dishonesty
I am sorry for not being honest about what happened. I understand that trust matters in a student-teacher relationship. I accept responsibility and will be truthful going forward.
For ignoring instructions
I am sorry I ignored the instruction and created extra difficulty. I should have listened and asked if I was unsure instead of doing something different.
For a repeated mistake
I know this is not the first time this issue has come up, so I understand that another apology alone is not enough. I am sorry, and I need to show the change through my behaviour.