Recognize what makes this moment difficult
Acknowledge the event directly without turning it into a lesson, comparison, prediction, or silver lining. For a message about how to apologize for not helping with a group project, use this factual base: name the assignment, rule, person, or shared work affected and do not conceal the extent of the problem.
Offer support that can be accepted
Offer one specific form of practical or emotional support and make clear that no immediate reply is needed. Ask which repair is permitted, complete your own work, and accept a fair academic consequence. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Follow their pace rather than yours
Do not pressure a teacher or classmate to erase a consequence or support a false account. Report bullying, threats, abuse, and safeguarding concerns to a trusted adult or official school channel. The recipient decides whether they want conversation, ordinary company, practical help, professional support, or quiet.